Sick Budgie

I recently got a budgie a couple months ago, shes a young albino, recently I've noticed that shes been bobbing her tail alot, shes also been doing numerous things as well, like ruffling her feathers, hunching over/crouching on her perch, she also is eating less and less, and wont touch her water bowl, and refuses to drink, today I notice her opening her beak wide multiple times, is she sick? Can it be fixed at home?