I said the same. That she could not be around my kids and unfortunately he has had her around them every time including an overnight stay on holiday. Even when my kids asked him he didnt comply - unfortunately he is not thinking properly at the moment. I had to resort to a letter from my L requesting it. This totally flipped him out and he called me all sorts of colourful name. It really hurt, that he can defend someone he has only known for 2 years rather then the mother of his children.
It will be his loss though as my kids are starting to stay they dont want to go anymore.
I think you did the right thing but putting in a boundary so early, unfortunatley I left it too late and so she already knew them. She had been to my house a couple of times without me knowkiing whilst he had them over the holidays. I have never met her - when I aksed I was told no as he thought I might do something to her. WHAT!! I am not a violent person and if she is only a frined why would I need to do anything to her????
Stick with it - do not let her near them.
Me 37 years young!! S11 S7 T22 M14 D final 13.05.2010 Today is the first day of the rest of my life!!! First post: D Day has arrived