I don't think you should change, but in my family middle names aren't referred to much at all, and no one goes by initials. Does she think that that is what the family will naturally call him, or is she worried that kids in school will pick it up?
There is one babyname site that lists potentially bad nicknames. I looked up Amy, and sure enough, the things I was called were there (Aim toothpaste and Aimless). My maiden name was Ensor, so my friend used to think it was fun to call me Aimless Eyesore, but this was when I was in my 20s and he was joking, so I thought it was funny. Anyway, no matter what your name is, someone will find a way to make a not so great nickname, if they want.