If your daughter is not going to have social media, you shouldn't be on there in her place. Why do you get to peruse all the middle school happenings online and she doesn't?
That's my simple answer. You feel like a stalker because you are. Your daughter does not have an account, and is not interacting, yet you are patrolling.
I feel that if your daughter has any accounts, you are 100% justified in monitoring her activity in relation to her accounts and online relationships. But since your daughter is not allowed to be active on social media, you should stay off as well and stay out of it.
If you've seen some bullying online, report it to the school please. They will appreciate that. Since you know some stuff, you should call the counselor or principal at the school and discuss, then leave it in their ballpark. And I do think you should stop checking if it is not directly involving your daughter. Wasn't that the point of saying no to social media, to keep her out of the drama related to it? Don't you want the same for yourself?
(I'm a middle school counselor, and I would definitely appreciate a heads-up on stuff from a mom who saw some things online. If that mom started to call me repeatedly though, like she was the social media police of the Jr. High, I would begin to think she was a whacko. But I think one call to get it all off your plate would be the way to go).
We can't control what other people and their kids do online But we can control our involvement in it, and our children's involvement.
PS ask.fm is by far the woooorst I would stay as far away from that one, just FYI to any other middle school parents who may be reading this.