I blocked this lady I don’t want in my life

I blocked her from calling/texting me and on fb after she found me there. I met her a few summers ago when I was on holiday with my parents. And now her kid and my kid are at camp together by chance and I’m definitely going to run into her and she will DEFINITELY bring up that she knows I blocked her. And/or she will pester my parents about getting in touch with me.

Also my kid likes her kid and wants to be friends.

What do I say ughhh