I wish your little one well, but unfortunately, we aren't a substitute for an avian vet
. There can be so many different causes for what might seem like the same symptom.
Birds with their wings clipped who want to fly to a certain point and know they can't will crouch down and quiver the wings a bit. Or sometimes they will flip their wings to get feathers in place. But if you just have a 'feeling' that this is not a normal behavior, I know you said you can't go to the vet, but that is the answer most people will give since that is really what your bird needs if you think something is wrong. Is there a possibility that you could borrow money from someone for an avian vet, even if it might be uncomfortable to ask?
I can tell you that I had a budgie who had "vibrating" wings a lot of the time. Could that be what you mean? Vibrating, as in quivering them as fast as a budgie can, as if sitting in one place while pretending to be a hummingbird if that makes sense? Pix did it so fast that you could hear the buzzing of his wings, and they were a blur to watch. Unfortunately he had many genetic things wrong with him which caught up to him at an early age and passed at under 2 years old. This neurological symptom was only one of the many symptoms Pix developed as a result of organ and system malfunction due to bad genetics or inbreeding 2 different vets thought.
I hope that didn't scare you, and I hope your bird doesn't have anything similar, but when you ask about twitching wings, it reminded me of Pix. Again, I hope that is not the case, as I of course can't 'diagnose'. Good luck...
Would it be possible to get a video of your bird doing this?