Wow, thank you all for the replies! I really wasn't expecting anything, but it felt good just to get out some of my feelings.

To healinghearts - I agree that she is an unhappy person. She's been like this as long as I've known her. But as for her jealousy, I really don't know. Jealous of what, exactly? My friend has suggested the same thing but I can't think of a single reason why she would be. I'm definitely not going to let her stop me from being a bridesmaid. I've talked to my brother about it and he agrees that she is out of line. He said he was going to talk to her about it but he has so much on his plate right now planning for the wedding. I don't want to add to his stress.

Riotgrrl - No, I've never tried talking to her about it when we haven't been arguing. I have told her how I feel and she just says that I will be alone like my mother if I don't find someone to spend my life with. (BTW, my mom just never remarried.) I pretty much breathe a sigh of relief when I see that my stepmom's not there. She will always say something. The thing is, she thinks that she's helping. My female relatives have started asking me if I am gay. When I asked them why they were thinking this, everyone's replies begin with "Well (stepmom's name) said..." I will try not to let her comments bother me.