Bridesmaids drama

Well, hopefully they are both adults, and will act accordingly. It's a very short time that they'll have to be standing next to each other. Then they don't have to interact the rest of the time. But really, speak to both of them if you have to. This is your wedding, you want them both to be a part of your special day, and you don't want there to be any drama during planning, or during the wedding/reception. It's really all you can do. Good luck!

Just talk to then. As Cristy said, they’re both adults and should be able to behave themselves

I agree that hopefully they’re able to be adults and put their differences aside for your wedding.

Sit them both down together and be straight with them. "You are both very important to me and I want both of you to be in my wedding party. If you think that you will be unable to put your differences a side for this important even in my life, then please do us both a favor and excuse yourself from being apart of my wedding party. Weddings are stressful enough and I simply can not deal with any additional stress."

If they still can't get along, then give them the boot. They should be able to put the past behind them to be there for you. If necessary, recruit another bridesmaid to "be the bad guy" and keep tabs on the other two.

Drama is to be expected but maybe try to let them know that you don't want any drama and have a talk with them?

They're adults they should be able to put it in the past! Either way they would both be at the wedding so would have to at least be cordial. If they both love you and want to be there for you they can suck it up. I would talk to them both separately first and let them know the situation.