<human>: Can you condense the text into three sentences or less?

I'm 30 and female, she's 36 and the 2 girls are 13 and 16. I like the girls, nice and easy to be around.
I bought a 4 bedroom home and have been looking for a roommate....1, mind you, not 3.
So my friend's boyfriend broke up with her earlier this week, but he doesn't plan to move out of their shared rental home until January. She told him she couldn't live there and pretend to be normal, and asked me if her and her girls could move in december 1st.
I'm not excited about this, but willing to see how it goes, until last night.
My friend and her "ex" were hosting the boxing match last night and she wanted me there for moral support.  What I witnessed was the classic girl-thinks-if-she-throws-fantastic-party-and-laughs-hard-enough-boyfriend-will-realize-how-awesome-she-is-and-want-her-back scenario.
Now I'm stuck feeling like she's not over him, and while it's been barely a week and I get that, I can't have her move in and decide a week later that he's somehow moving in too.

How do I bring this up to her? I have a tendency to be cold and direct and could use some advice on how to approach this...nicely.
<bot>: friend wants to move her and 2 kids into my house, she hasn't accepted a recent breakup and I'm scared she'll expect her ex could move in in the future. What should I do?