From My Experience

I've been with my husband for about 4 years now. Through out which we had a long involved custody battle with the ex girl friend (she wasn't even his wife) over my step daughter. When we were first together, she made our lives hell in every way that she could. Nasty texts, nasty voice mails, phone calls, with holding my SD and any information having to do with her. Here's what my husband and I did and it worked for us.

1). A legal custody agreement. You most likely have one but if you don't it is imperative. Therefore, the law states when you have visitation with the kids and she can't do sh*t about it. Once that document is drawn, if she violates it she can face punishment by the court and eventually lose the children if she behaves in a way that is unfit for the them (I.E. she shows her ass to you or you SO in front of the children). It's a long process but establishes some stability.

2). He changes his personal cell number and purchases a pre paid cell phone he can carry to contact his children, can check for emergencies and is a way for her to contact if she needs to. The phone can be checked twice a day and turned off. This prevents her texts and all that garbage from disturbing you and him. She may still be mean and ugly but at least those harrassing message are not on your SO personal phone and you can save them to the pre paid phone's inboxes so that if you do go to court, you will have them as evidence of her behavior. This way, it's not front and center and he doesn't have do worry about picking up his cell and seeing some crap from her.

3) SO and crazy BM agree on a place to meet and pick up/drop off children that is neutral, not at your home. My DH and BM meet at McDonald's and he picks up my SD. He has nothing to say to her and usually if she say something, he says "If it's important and about my daughter, leave a voice mail one the phone and I'll get back to you" and he leaves. The whole pick up/drop off takes 5 minuets. This gets her the hell away from your home. If she still comes by, call the cops if she doesn't leave. Don't warn her, just do it. Only action is going to make her respect your boundaries and your relationship with your SO.

I feel that you have every right to go to any function that your skids have as long as you are married, there is nothing she can do. If she acts a fool in public, walk away for the sake of the kids and document for the sake of going to court in the future. Just in case...

The only way that her craziness and inteference in your lives is going to be minimized(believe me it's not ever going away completely if she's a jealous b**ch)is if he cuts out the unncessary communication like arguing and texting and only speaks with her in reguards to the children and hangs up the phone/walks away when she start in on somethings else. Honey, I've been there and the majority of this is something he has to take care of because coming from you is just going to piss BM off and make her do even more to cause interfernce. If he values yours and his peace and your lives together, he will do this. If he doesn't get her out of the middle of your lives then you may need to re evaluate your realtionship. I'm not saying that to hurt your feelings, I can relate because I've been there. My now DH used to let his BM interfere all the time until I laid down the law and made him choose to respect our lives together or argu with her and let her have run of things... since then, we've gotten married had 3 years of peace for the most part.

I hope that helped. It worked for me. Good luck sweetie