Sweet daughter

What a way to start my blog... today my sweet daughter of 12 got invited to a birthday party for her friend. :) It was a bonfire/cookout/ birthday party.
I dropped her off with every intention of picking her up at 11pm. She called around 8:30 to ask if she could spend the night. Since she didn't have pajamas and her friend is not the same size (and other girls had been invited to spend the night prior to being at the party) I told her I'd talk to her dad and get back to her on it. I guess I wasn't quick enough because she called back. While I was discussing pajamas etc. with her she asked the friend if she had any extra shirts for bedtime so I wouldn't have to drive all the way back... she suddenly was uninvited to spend the night b/c "her mom said she already had enough girls staying over".

Am I being an over protective Mom to say WTF!?!? Who un-invites a child like that? My dd didn't seem to have a problem with it, but I just have a bad feeling about the whole situation. She was invited last minute to the party, though they are in the same homeroom Monday- Friday. Then she is invited to spend the night after she has gotten there. Then she is un-invited from spending the night... I think that would have hurt my feelings at 12 years of age. Maybe. I don't know I possibly wouldn't have cared at all. I've gotten more emotional since I've had children. :(

According to my dd there were other girls who did not spend the night, or were not invited to spend the night. She was not singled out in that respect... but for her to be invited and then not is what is bothering me.
She has been friends with this girl for some years now. They were closer friends at a younger age and now see one another in school, but not much out of school.

Please let me know am I being one of those Mom's who get too involved with their children's lives?? or do I have reason to feel bad for her--- even though she doesn't seem to care much??