So in a nutshell, there was a girl I originally wanted to be a bridesmaid but she went to go live with her parents in Bolivia in July and basically cut off all communication with me. My wedding is this April and being that this girl never sent me a message or an email or anything I found a replacement. I asked another friend of mine who was gracious enough to accept. Because the girl I originally asked was no longer in the wedding I selected a couture bridesmaids gown that does not come in plus sizes.
Well my fiance was on facebook yesterday and she had a status saying she was coming home next weekend, AND she sent him a message (I don't have a facebook) saying how excited she was to finally go dress shopping and help plan for the wedding.
I went straight into panic mode. I've been friends with this girl for 15 years and neither of her sisters had her in the wedding party so I feel obligated to have her but she's a bigger girl and she WILL NOT fit into the dress I bought for the rest of my bridesmaids.
Oh FYI, the only reason she's coming home is because her new boyfriend begged her to, just a character reference.
I'm offended she didn't feel the need to keep in touch with me if we're really "best friends" you'd think she'd email or something, and now that she's coming home she suddenly assumes she's still in the wedding.
What should I do?
Do I tell her she's no longer a bridesmaid? How do I do that without hurting her feelings?
Do I let her be a bridesmaid and make her wear a different dress?
I'm still really angry at her, so I need advice from someone objective.

PLEASE NOTE! THIS POLL IS A JOKE AND NOT TO BE TAKEN SERIOUSLY.
UPDATE 2/22/2012:
My friend has yet to come back to the country. Her boyfriend left her, and because he was her original motivation for coming home she is prolonging her stay in Bolivia. She has posted on facebook that she will be back "in 2 weeks...I hope".
I unfortunately was met with a lot of hostility because of this post. I did report and/or block anyone who left hateful or rude remarks about me or any other contributors.
I am looking for genuine advice, not a barrage of insults. If you disagree with me, tell me in a way that is tactful please.