Welcome! Where is Medway?
If the clutch already has 6 eggs in it, then you can go ahead and candle them, and at least the first 4 or 5, if not all 6 (I don't know how long ago she finished laying the clutch) should show whether or not any of them are fertilized. That way you'll be totally prepared...All you have to do is wait until the female/both adults leave the nest-box for food/drink and block-off the entrance with something, like a piece of cardboard (you need to get ready to do this every day, even if you're planning on letting the parents raise and feed the babies, which you should; you'll still need to handle and talk to each baby every single day from the age of 2 weeks onward in order to tame them)...Hold each egg up and place a flashlight behind the egg, facing you, so that the contents are illuminated. If you see simply an egg with fluid/yellow inside of it and that is otherwise clear, then it's not fertile (if it's been laid in only the past 3-4 days it may still be fertile and you'll have to check it again in a day or two). If you see any veins at all, it's fertile. If you see any solid objects inside the egg where the light won't pass through the egg, it is usually fertile. Keep in-mind that not all fertile eggs will hatch, things happen. The incubation period for Lovebirds is about 23 days, and each egg was laid a day or two apart. So you need to also remember that even if none of the eggs hatch on day 23-24, and any of them look to be fertile, you have to let them all in the nest-box for at least another 2 weeks after the 23 day mark, because it could be that only the very last egg that she laid is going to hatch, but that egg will not hatch until long after the 23 day mark, with 6 eggs, the last egg won't hatch until around the 35-37 day...
I'm assuming that you're planning on letting the parents raise the babies inside of the nest-box and letting them feed them, correct? If you have no experience hand-feeding baby birds formula with a syringe, or aren't able to feed the every 2-3 hours for the first 2 weeks after pulling them from the nest-box, including overnight, then I don't suggest you try to do so (you have to pull them no earlier than 2 weeks old and no later than 3 weeks old). Hand-feeding them makes no difference anyway, it's not the "hand-feeding" them that makes them hand-tame, it's simply them being handled, interacted with, and spoken to every single day from the age of 2-3 weeks old up through abundance-weaning...
***Just to squash one total myth that is popular on the internet (in case you've read it), you will not cause any issues at all by handling either the eggs to candle them, or by handling the babies every day to hand-tame them and then putting them back inside of the nest-box for mom and dad to feed and care for. Handling babies does not cause the parents to abandon them in any way, your "scent" will not "stick to the babies" and scare away or anger mom or dad, etc. In fact, the most responsible way for anyone who is not an experienced bird breeder to end-up with a clutch of sweet, cuddly, hand-tamed baby birds is for them to simply allow mom and dad to both raise and feed them from the time they hatch until they fully-wean, allow them to live full-time inside of the nest-box and be heated by mom/dad, and for them to simply wait until each baby bird is at least 2 weeks old but never any older than 3 weeks old, and then start blocking off the nest-box while mom and dad are both outside of it, and then to gently pick-up each baby out of the nest-box, sit down in a chair with them (put a comfy chair next to the cage), and sit and hold, cuddle, pet, scratch, and softly talk to each baby for at least 15-30 minutes every single day. It's important that you handle each baby every single day, you can't skip days, and it's also very important that you not wait any longer to start the hand-taming process than when each baby is 3 weeks old (remember that each baby is a different age by at least 2 days, so don't wait until each baby is 3 weeks old! You need to find a way to keep track of each baby and start hand-taming each baby no sooner than 2 weeks old but no older than 3 weeks old, so be sure that you don't wait any longer with each baby!) A lot of people make the mistake of waiting until all of the babies in the clutch are 3 weeks old, and that will almost always end with only 1 or 2 of a larger clutch being very tame at all.
I would get a notebook and pen and keep it next to the cage, as well as different colors of all-vegetable food-coloring, a different color for each baby that hatches. Then when the first baby hatches, choose a color for them and put a single dot of that color of food-coloring on that baby's back, and then right down in your notebook the date that the first bird hatched, and what color dot he has. That way you can easily keep track of each baby's age, and you'll know exactly when each baby hits the 2 week-old mark so you can start handling each of them at exactly the correct time. Also, this way you'll know each baby's birthdate.
If you have any questions at all about anything, please don't ever hesitate to post on the forum...the "Breeding" forum is full of great "stickies" on everything breeding, hand-raising, hand-taming, weaning, etc. And if you have a specific question, even though you're new and can not yet PM regular members, you can however PM any moderator...
