why does my parakeet lift her left wing?

by Priyanka
(USA )

my conure

my conure

my conure

the wing that was bleeding
this is how she does it (sorry its a little bad she was moving)

I have a parakeet I'm not exactly sure what kind but I've had her for about 2-3 months and she doesn't know how to fly yet. I got her from a pet store and ever since I got her at times she would lift up just her left wing. I don't know if she has done this from the start or not. She does this when she is sitting but mostly after she jumps off of something for example a bed or from the top of her cage (which makes me worried that shes going to get hurt).

I have tried to look at her wing but there's nothing under it or around it. I have another bird i'ts a conure. One day I looked at my parakeet and her wing was bleeding from the edge and one of her feathers was sticking out with blood inside it. My parents and I were going to take her to the vet but the bleeding stopped pretty quickly so we didn't. We were thinking that my conure may have bit her or something but didn't know for sure what happened. I have tried to keep her in the cage but have 3 other parakeets which she likes to play with outside the cage. Can you help?