This is a very short question but I cant find anything online about this. My grandma thinks my bird has a problem with her leg, she thinks she has a bump on the (knee? back knee? idk what it is) but I think shes fine. She thinks that she stands on one leg because she has a bad foot, but I already know that birds stand on one leg to rest or to get heat. To make sure, I looked up "bird foot problems" and I can't find any bird foot problem online that looks like her "problem" I doubt she even has a problem with her foot and my grandma is overreacting. I gave those details to get better answers but my main question is: is it normal for a bird to always stand on one specific leg? Thats one of the reasons my grandma thinks my bird has a problem with her foot, even though I doubt it. Answers please. 
: She now flies to me all the time and bites my earrings and she now looks like this! (This is the pic my mom sent me right after they managed to clean her cheeks, so, shes very wet.):