I remember there is a member here who was experiencing some really bizarre behavior from her unaltered female, and after she was spayed she was a lot better. Hopefully she will see your post and share some insight. Sorry I'm no help, with no female dogs (I've got three boys here).
Hi Kerby, the first heat can occur quite early, watch her for the next two weeks and see if she starts bleeding, also swelling in the area is a clear sign as well. At the age of 8 months, she is going through hormonal changes a.k.a "the teenage" years :)