Weddingbee boards

I need help! A little background: I have 1 maid of honor and 1 bridesmaid. The three of us used to be inseparable not too long ago, we even have matching tattoos. So when I got engaged, there was no question that they would be in my wedding party. At first they were both very excited and helpful, but that faded fast. I didn't mind, I haven't asked them to do ANYTHING except get their dresses. I thought have only 2 bridesmaids would save me from drama, but I was wrong.

My bridesmaid knew that she was going to have to pay for her dress - 120$ which she and the MOH picked out and agreed was a reasonable price. I asked her before we ever ordered the dress if she was sure she could handle the financial responsibilities and she assured me it wasn't a problem. She had just gotten a 700 refund check and I told her she should save some for the dress, but of course she promptly blew it on who knows what. My MOH ended up paying the first half for both the dresses, (60 for each) so that they would be ordered and assumed that BM would pay her back. I was a little upset that she did this, I knew she was trying to be nice but I was concerned BM wouldn't pay her back and wouldn't have the rest of the money (another 60) to pay when the dress came in. MOH's dress came in first, BM's a few days later. When MOH told BM her dress had arrived her response was "Gross." She ended up picking up her dress (past the deadline the store had given her) and paying the second half with money she borrowed from her dad but still owes MOH the other 60$. After a couple weeks of barely hearing from her or seeing her, I again asked her if being a bridesmaid was too much for her and if she wanted out, which she adamantly refused. I flat out told her, if you don't want to be in the wedding all you have to do is say so, I just need to know now.

3 weeks ago BM lost her job. *Quit* her job, I should say. Still went on a 10 day trip to Colorado. I didn't see her for a week before she left and she's been back for 5 days now, we were supposed to hang out one day but she blew me off saying she'd slept all day, yet posted on her FB status that she was so happy to be spending the day with another friend of hers. Haven't heard from her since then. She and MOH still need shoes, dresses altered, and accessories. The wedding is 3 months away. I don't feel like I can even bring this stuff up to her because she has absolutely no money and I also feel like she doesn't even care. She didn't even try on her dress when she picked it up. The past couple of months I have barely seen her and she never tries to contact me. 

What should I do? I'm afraid if I ask her if she wants to be in the wedding she will still say yes. I'm afraid if I tell her I don't want her to be in the wedding and that she is out, I will ruin our friendship, although at this point I'm not sure we have much of one anyway. If she isn't in the wedding I won't replace her. I should mention that she is younger than me (she's 20, I'm 24) and people tell me that's she just immature but I don't think that's a good enough excuse. At this point I don't even feel like talking to her!