"Dating" in her words just means boyfriend. It's not like real dating the way it was when I was younger.
A lot of the Middle Schoolers have a boyfriend or girlfriend and it is nothing more than sitting together at lunch, etc.
When my daughter was about 12, she did go to the movies with groups of friends which was coed. She did not have a specific boyfriend at the time. It was just a large group of friends, dropped off at the movies by parents and picked up by parents.
I never made a huge deal about it because I have seen other parents who have made a huge deal of it end up with their girls sneaking out, etc.
My policy from day 1 was side open communication lines with daughter... no topic is off limits. We talk about EVERYTHING.
Of course on these friends to the movies outings, I made sure she was aware of what some boys are after, how to handle herself, etc. My daughter is a black belt and you just touch her wrong and she will lay you out cold.
I don't think it is that big of a deal as long as you are both open and honest with each other, including your fears for her and your expectations of her.
My daughter is 16, all honors, AP classes, cheerleader, very driven to excel, responsible young woman. I have been known to comment when she now goes on dates with her boyfriend who is attached to her hip basically that goes like this "you guys be careful, you know how a baby would throw a huge kink in your plans for your studies in Italy and your college". Of course, I get the "oh MOOOOMMMMM" but the message is out there..
They have to socialize so when the day comes when they do date one one one, they can get along with and relate to others well. We can't let them live under rocks all their lives and then expect them to not rebel when they are let out!!
Communication and Moderation!