Fun things to do in Pittsburgh in the winter!?

HELLO!!! okay so my family (mom dad and little brother and me!) are going to Pittsburgh in September October November or December!!!! Tpwe are going to go visit 2 boys , jack, who is 9, Cole who is 8. I am 12, so far we have going to a hockey or steelers game, play laser tag, and just hang out!!! What else should we do? I have never been but I'm very excited to go!!!:) My dad has been so its not like we are TOTALLY lost, we have the boys 2 . So do you guys have any good ideas on what to do!? Thanks guys and god bless you all!!