Do you monitor her weight? Kitchen gram scales and a square deep plastic food storage container work very well. Is the weight consistent up or down more than a couple of grams? What do the droppings look like -pic? Feel the chest muscle on either side of the keel bone if you do not have a scale is your bird English or the smaller type from the pet store. What and how much is she eating seed/pellet/egg food/ veggies/sprouts?
Do you play/exercise with her out of the cage? does she pant after flying? How many cycles around the room to stretch wings before settle down? Could she be hot? Hold her close to your ear and listen for crackling above the steady sound of the heart beat. This could be a respiratory illness. Is there any dark smudges in feathers above the cere? does she sneeze or have moisture around the cere?
Hold her facing away from you with her tail close to your chest . Gently extend each wing and check for tenderness above and below along the bones of the wings. I close my eyes and visualize as I go along the wing. Look up wing structure if you are not familiar with anatomy. still holding with one hand press thumb and first finger just above the vent on top and below the base of the tail. a small lump will be the oil gland an enlarged growth could be a feather cyst or a tumor. Examine the back under the wings for any lumps or wounds, Turn bird around and check for any abnormal lumps on chest area.
Examine eyes and ear hole for redness, swelling or excess fluid or missing feathers. Is the bird molting? are there pinnies on head and tons of feathers on the bottom of cage more than normal. Double check this and droppings by changing paper 2 times a day to see what you find. Examine feet and beak for evidence of scaley mites -crusty growths on the feet /legs/beak /cere/ skin under the beak? possible on the edges of eyes or the vent.
Check the vent area for clogged droppings or mites. does she need deworming? Do you see and tiny bugs crawling in feathers?
Start your bird on electrolyte like avitech sugarless sold by ladygouldianfinch or windy city parrot- both ship international and add a probiotic and alternate three days a week With Braggs ACV- usually available at health food store -has mother in it. If she is molting get some flax seed from pet store or health food store to support new feather growth. What vits or minerals does your bird get? Do you share people food?
Make a list of above and comment on each . High light or check off any problems identified. Vomiting? coughing? If needed make an appointment with your avian vet and take you list of weight and answers to above. This includes easy immune boost things as well as areas like diet that may need work. If you are feeling down your bird can pick up on this and be effected. play some music/tv or you tube bird sounds which should encourage response and chirping/singing and moving about the cage. Others may think of things I have missed.
I hope this helps to reveal any problems. A couple good clear pics of front /back/tail/legs face/beak/ cere or any lumps you may find. Lumps can be small like a seed or pea or large/soft or hard. I hope both you and your budgie are feeling better. B Vits are really good for energy for people and budgies B complex and a time release B12 often in a women's formula
Best wishes, Jo Ann