Well when I invite she brings her son out kids are the same age but she just refuses to sleep here even if it’s clearly the better idea

I'd mention this to her in the same way it was posted so she sees what it looks like .
For some random . But not a bff sleepover party ???? Y wouldnt she ?????

It could be the whole your daughter might get up whenever and they don't want to be woken up.

I'd still be slightly upset though.