Gosh, Limbo I just read this whole thread and I agree with the good advice you got. I think OW is trying to play a game to hurt you and destroy your marriage further (she is one crazy manipulative bit@h!!!). The very best thing is to ignore her and let your husband see every message she sends. This will bring you both closer (eliminates secrets) and he can see what a mean-spirted evil person she is.
So don't engage her in any more conversation. If she continues to try to contact you, let her know you will file a restraining order. Keep a copy of all records for your file in case you do need to file one of these.
Try not to be too angry with your husband. We really don't know what was true or not true and having your family together NOW is more important then this crap from the past. Today is the only thing that counts, and having your kids raised by their father is what's important. If you are hurt and angry just take a breather (let him know you just need a bit of space), and just work on being "friends" with him while you work through your emotions.
{{{{hugs}}}}}
There is no arriving, ever. It is all a continual becoming.