5 month old budgie vibrating / shaking alot

[Amsterdam]

hi guys,

so i have a new budgie its a she and i keep her alone but my other budgies seem to like her when i open the cages they all fly to her to play ( not aggresive ) how ever its getting colder 25 C atm where im staying and shes vibrating her wings alot is she uncomfortable or in pain? also i noticed that her butt has a big bald round circle which non of my other budgies ever had should i be worried??

 

[Amsterdam]

i forgot to add that i have her over a month and i see this now for the last week she also never is active or playfull how ever i managed to tame her what is wrong with her?

 

[Laurasea]

Hi Amsterdam!
Picture please
Could she be egg bound????? You can very lightly like you are touching your eyelid feel her belly and by her vent see if you feel an egg? How do poops look?
Supplemental hest always helps sick birds, you can do the lamp think like I had you do before.
I'm glad you are still Rescuing birds!!!!!!! Thank you

 

[wrench13]

All signs of a sick birdie, I would seek CAV like now. The bald spot especially is telling.