Pionus only seems to pluck when i'm around?

Hi all, first post here. About 4 months ago, I adopted a Blue Headed Pionus named Marley. Her previous owner died, and her son asked me if I would want to take the bird, as i have always loved birds and have wanted one for as long as I can remember. When I got her, she was fully plucked, with the exception of her head and a couple of feathers on each wing. She was drinking from an old water bottle, and was being fed cockatiel seed mix every day for almost 18 years. Now that I have had her for some time, I have been trying to convert her to a new diet, consisting of various fruits and veggies in the morning, alongside a dish of Lafebers pellets and a couple of nutri-berries with each meal, and offering seeds 30 minutes or so. I have also been grinding up pellets, cereal, and sunflower seeds to make a hand feeding formula for her to make sure that she at least gets some of her proper nutrition in. For the first couple of months, she did seem to be growing her feathers back, and was slowly but surely getting more and more fluffy as the days went by. but for the last month or so, she has been plucking the down feathers out again at night.
Personally, I am not bothered having a plucked parrot. I love the little bird to death, take her everywhere with me around the house, and she even sits on my shoulder while I work on my bicycles in the back yard (as she cannot fly). Since it has been sunny out every day for the past week or so, I have been putting her outside in her travel cage in the morning, checking in on her every 20-30 minutes until I have to go to work or school.
I have been trying to think of the changes that have been made to her lifestyle lately, but the only 2 things that I can think of are trying to get her to eat new foods, and my girlfriend and I breaking up, though my ex did not care to be around the bird (she got jealous that I spent money on the bird...).
I did take Marley to the vet to get her checked out, but was not able to afford the blood test at the time. I am going to take her back sometime this week and see if I can get that done. I did, however, have a stool test done and the veterinarian told me that she did seem to be malnourished from the types of bacteria that she found.
So, any ideas on what could be causing this recurrence of plucking?

As a side note, I can leave her for a couple of hours and she will be just fine, no feathers at the bottom of her cage, but she starts plucking after an hour or so of being around me, unless she's riding on my shoulder. She does get covered up at night, but I am going to try and not cover her tonight, or only partially cover her.

Hi, I'm sorry that Marley has begun to pluck again. It's such a complicated thing, and there are so many reasons for it. Here is a great "sticky thread" that you might be interested in reading. It has lots of information on the topic. Best of luck to you and Marley.http://www.parrotforums.com/behavioral/52217-plucking-search-answers.html

My grey Tallulah does this too, she gets to the point where she's had enough and wants to go back on her cage, but will still keep trying to come over to me. I haven't really pinned it down to anything either, other than a nervous habit and maybe not being used to being handled as much. I'm trying to limit how much I'm holding her at each time, giving her a decent break inbetween and trying to distract her from plucking. She's fine if I'm petting her for the most part, but evenly it's to the point where she needs to go back, which I try to keep her from getting to that point.