Ex in-laws PLEASE HELP

So my daughter is turning three. Her bio father has told me he doesn't want to be part of my daughters life cause his girlfriend means more than her. But I am had issues with his mom before. I am trying to be nice and invite people to her party that care and are her family, but his mom has never made effort to call me or anything. Until I just invited her to her party and she asked if she could take my daughter out when she barely knows her. How do I nicely say I prefer to have her be with me and I don't trust her? I want to shut her down nice, but I don't know how. I want her to see me and her, not just one on one time.

Tell her that your LO is skittish around people she doesn't know of you aren't there.

Yup I would tell her she is very stranger shy when mom is not around but you'd be happy to make plans for lunch or something sometime and maybe she will come around more. I have the same issue with mine. My daughter calls her "xmas grandma" cause it was the only time she would ever see her lol