Also for those that follow. I did tell her I want to meet at the indoor playground next Saturday. All I said was this is where this is when for S1 bday and the kids can play. I did not invite her to stay, I also did not tell her she couldn't. If she wants to that would be great for the kids. If not I don't care. It's not about her. It's about my family, me and my kids.
She seemed confused and caught off guard by me telling her this. Her response was a seemingly indifferent ok ya I will meet you there.
The person that you will spend the most time with in your life is yourself, so make yourself as interesting as possible.