I think thats not Spider-girl, but Spider-Woman. It is most likely a female Peter clone but I was hoping it was Gwen Stacy, but that looks to be wrong. Oh yeah this is my first post, so see yall around.
I'm pretty darn sure she's a female clone of Peter. After she knocks out Peter she makes a comment about how "I'll get them back for you, Peter. I'll do it for all of us.". This leads me to believe she's talking about the other Peter clones.
That would be a very interesting idea but I still want to see Ultimate Scarlet Spider. They did say that a unmentioned character will get his/her debut. It would be very cool if Jessica Drew was a Peter clone.