I'll try and keep this short, as I am trying to get outside opinions here.  I called my BFF after I got engaged several months ago and said "Get ready MOH" to her.   Since then, she has seemed completely uninterested in me, my engagement or my wedding.  Do I need to offer an explanation when I ask her to be a bridesmaid and not MOH?  My fear is that she won't be my friend anymore if I DON'T make her MOH, but she really has shown no interest at all in my wedding whatsoever and has already started using her 1 1/2 year old as an excuse for her lack of interset (legitimately, she said she hadn't asked any details at all because she's a mother).
 
Thoughts?