Welcome to the Community Brooke! And congrats on bringing Petra into your family, you're going to have a wonderful, long life with her! IRN's make wonderful companion parrots, and though I myself have not ever owned one (though I have spent tons of time with a few IRN's that have lived at the Rescue I volunteer at, and they have all been wonderful, intelligent, and loving birds), there are a few specific members here that have long-time experience owning, raising, and breeding IRN's, and who know practically everything there is to know about them, and can help you with all of the questions you are no-doubt going to have. And please don't ever hesitate to ask any questions that you do have, there is no such thing as a stupid-question, that's for sure...
As Scott already mentioned, you've only had Petra for less than 24-hours, so it's going to take a while for Petra to settle-in to her new home and with her new person, but it sounds like you two are off to a great start...The medium-size Vision cage will be fine for her until Thursday when her much-larger, permanent cage arrives...I have several of the extra-large, extra-tall Vision cages, which I love and so do my birds who have them as their main cages...And although the medium-size Vision cage is no where near large enough for an IRN to live in permanently, the bars of the Vision cages are extra-thick and made of galvanized-steel, so as far as the bar-spacing and thickness it will be fine for Petra. It's just the size of the medium Vision cages that is too small for her, but will be fine until Thursday for her...Just make sure that she is getting lots and lots of out-of-cage-time every day, as the medium Vision Cage is not quite large enough for an IRN to spread their wings out completely or to get much exercise (I don't know if you have the regular medium Vision cage or the double-medium Vision cage, but if it's the double-sized medium Vision Cage then it's actually not too bad in-terms of size, and would make a great "sleeping-cage" for Petra)...
Petra's "main-cage" should be huge, as large of a cage that you can afford and have room for, that's a great rule to follow when buying your birds cages...If it's one of those huge corner-cages then it should be awesome for Petra...Be sure that you place Petra's "Main-Cage" in the "main" room of your home, the room where all the "action" is, or in other-words, you want Petra's "main-cage" to be located in the room of your home where the people who live in your home spend their time when they are home. Usually this is the living room, the family room, the den, etc., usually the room where the main TV, stereo, video games, etc., along with the couches and such are located. The reason for this is because parrots are not only extremely intelligent (the intelligent of a human toddler, literally) and they know when people are home, even if they can't see them, but because parrots are far more-likely to learn to entertain themselves if they are in the presence of the people who are at home...For example, a lot of new bird owners decide to put their first bird's main-cage in a spare bedroom or office that is away from "where the action is" in the house, even designating this room the "bird room"...While this is well-meaning, it usually ends-up in a situation where their bird starts screaming for hours and hours each day. Why? Because if your bird can hear that you are home, or that anyone is home, but they can't see you and aren't in your presence, they feel totally left-out, and this creates unwanted and sometimes destructive and harmful behavior...However, if your bird's main-cage is located in the living room, family room, etc., and your bird is in the same room with you and your family while you are watching TV, reading, playing video games, talking, eating meals, etc., then even if you are not directly-interacting with Petra, just the fact that she is in the same room with you and the rest of the people who are in the house will give her a feeling of comfort, security, and make her feel like she's a part of the family..And this will result in her being happy to entertain herself inside of her cage, playing with her many toys, foraging activities, etc.
Now when I'm at home, all of my birds are out of their cages, and are usually either with me, or they are with each other (the bonded ones) playing on their play-gyms and such. Sometimes this isn't possible, to have your bird out of their cage whenever you're at home, though you should try to do so whenever you can (I highly suggest you invest in at least one portable T-Stand or Play-Stand that you can easily move from room to room, and that you can hang toys and things for her to chew on off of)...So if you're in the kitchen cooking dinner, take her T-Stand to the kitchen and put her on it, and talk to her while you're cooking dinner. If you're in your bedroom doing something, same thing, etc. And if her main-cage is located in the main room of your house, then during the times when you have people over and you're watching movies, playing games, having a party, etc., then she'll be happy to entertain herself inside of her cage, because she's in the same room with you and the others, even though you're not interacting with her...
As far as a sleeping-cage, some people use them, some don't, but it's typically a much smaller cage than their main-cage is, and it has no toys or activities inside it. It's just a small cage with a perch, a water dish, and maybe a swing if your bird likes to sleep on a swing. That's it. I do this, and my bird's sleeping cages are in my master bedroom. So they go to bed before I do, in my bedroom, i cover them for the night, and in the morning they get up with me, and then go downstairs to their main-cages to eat breakfast. This can ensure that they are getting the 12 hours of sleep every night that they need, and that I'm not disturbing them by watching TV or playing guitar as I often do before bed...So that medium Vision cage would be perfect as her sleeping-cage, if you want to go that route...
As far as diet, the IRN experts can give you more-specific details about any IRN specific nutritional needs...I didn't catch how old Petra is, if she's over 2 years old and has no ring then it's most-likely safe to say she's definitely a female, although many IRN people have mentioned that it can actually take up to 3 years-old for some of them to develop their rings...If she's over 3 years old then this is a moot-point, but it's important to be 100% sure of their gender, especially with a female, as you want to be on-top of any chronic egg-laying and ensure that she has a mineral block and a Cuttlebone during egg-laying, along with giving her either made or purchased Egg-food. This will help to ensure that she never becomes egg-bound, and that her body doesn't leech the calcium out of her bones in order to make shells...
I don't know what diet Petra is on right now, but if it's an all-seed diet and she is not eating pellets as her main-staple, then you definitely want to start transitioning her over from seeds to pellets as the main part of her diet...She should still get a small amount of a fortified, healthy, extremely varied seed-mix as a supplement to her pellets, as well as fresh veggies every single day...There are a ton of great "chop" recipes in the Food/Diet forum...And a bit of fruit a couple of times a week, but not a lot, as fruit is full of sugar, which is not good for birds, especially those in captivity that are not getting near the exercise that wild birds get. The same with fatty seeds, such as Sunflower Seeds and millet seeds, as they are extremely fatty and should only be occasional treats, so try to find a healthy, varied seed-mix without Sunflower seeds. The number one reason why parrots in the US die young is Fatty Liver Disease due to all-seed diets, and that usually contain a ton of Sunflower Seeds as filler...
*****The last and probably the most important bit of general parrot advice I can give you is that you absolutely need to find a Certified Avian Vet to be Petra's regular doctor. There is a massive difference between a Certified Avian Vet, and an "Exotics" Vet. Unfortunately the Exotics Vets are far more common, but they usually end-up doing more harm than good...there are exceptions to this, as there are some Exotics Vets who have much Avian experience, but they are not the norm, not even close...Most Exotics Vets go from seeing a rodent to then a bird, then a reptile, then a marsupial, etc. So they typically specialize in nothing, and are simply willing to "see" anything...This can be deadly for birds, who are extremely specialized physiologically and anatomically...So even if you have to drive several hours one-way to see the Certified Avian Vet who is closest to you, it's well-worth it. Finding an experienced, trusted CAV that you can form a relationship with is absolutely priceless...We can help you find the nearest CAV's to you, there's a search tool for this that someone will no-doubt post the link to...
You should take any new bird to a CAV within the first month of bringing them home, preferably within the first couple of weeks, for a "Wellness Exam", to ensure that everything is fine, there are no health issues going on, and also to start to establish that relationship with a CAV...And then your bird should have a complete Wellness-Exam at least once a year from that point on, and for an adult bird, you definitely want to get baseline-blood work done, not only to get an overall-picture of her health, but to know what her strengths and weaknesses as far as her health are, and what changes you need to make to get her heading in the right direction (a routine Avian blood-panel includes Liver and Kidney functions tests, as well as a Metabolic Panel, to that you can make any changes to her diet as early as possible, to prevent things like Fatty Liver Disease or Kidney Disease)...
