Mike and Nicole’s OPP: To Be or Not To Be…in a Wedding

Dear Mike and Nicole,

I'm in a bit of an uncomfortable situation. A friend of mine is getting married and awhile back informally asked me to be in her wedding. Please keep in mind, it was first time I had seen her in nearly a year and no solid answer was given. I don't know her fiance at all, she and I aren't close anymore and I work in the wedding circuit, so I feel like that is the only reason she wants me in the wedding. I don't want to be her bridesmaid. I've been in a number of weddings in the past. It's a lot of work, a lot of money and to me it is an honor and responsibility that should be taken on by close friends and family. But that begs the question, am I a close friend in her mind? She hardly spends time with any friends since she started this new relationship, so that is possible. Which also makes me think it's not a very healthy relationship. I tried to hint at the fact that we aren't close, but she brushes it off and keeps trying to formally ask me. Is there a good way to say no? We used to be close, I don't dislike her and I don't want to hurt her feelings. Am I being selfish? Should I just suck it up and do it? Please help!