This is a battle worth fighting. Seriously. Only you know your daughter though. If you drop them off at the mall, there are places that are off the hallways to the bathrooms, places they can go to be alone. If you drop them off at the movies they can sit in the dark and make out or even have sex by her sitting on his lap.
If you drop them of at a school activity they can sneak off to the back bathroom. Kids this age do NOT have the skills to not feel pressured into a sexual relationship. They just don't have the ability to say no and not get tricked or talked into just a little thing like letting them see "it". I'll show me mine if you show me yours.
I seriously do not believe kids this age should be alone anywhere. If you aren't there to supervise then I suggest you realize they are going to end up doing things they shouldn't be doing.
I will not drop the kids off anywhere I am not there with them to directly supervisor. I will not allow them to date until they are 16. Period.
Kids should not date in singles at 12. What are you thinking?
She should not even going to school dances with guys at this age. The group thing is still what they should be doing. When they're 14 maybe I'll take them to the movie and I'll go to one and them the other. When they're 14 they might get to walk around at the mall but I'll still be there with them in the same area.
When they're 16 they'll have the skills and understanding of how their body works and how wanting to have full out sex is something that happens but it should not be acted upon if they don't want a baby coming a few months later. They are old enough to understand the consequences of their actions.
At 12 your child should still be playing with dolls and video games. Not dating. What are you thinking?