Bridesmaid doesn't want to wear dress

I have a certain bridesmaid who back when I first got engaged, she asked me to be a bridesmaid and I was so excited I said yes! I should have been smarter and realized it wasn't a good idea, as her and I aren't that close anymore. She's never been to a wedding before and doesn't believe in marriage. She didn't say anything about not liking the dress but it took her until just a few weeks ago to order it and she said it just came in. When I asked about alterations she said it's way too long but it doesn't matter because she's only going to wear it for the ceremony. I explained there won't really be a great time to change into the dress since we're doing pictures and then have a special entrance into the banquet hall. She also doesn't want to come to the rehearsal dinner and is just acting like she doesn't want to go to the wedding. She hasn't replied to any of my texts in a week so I don't know what her thoughts are. I just wanted to share. I feel stupid for letting this happen.