There are lots of things that it could be:
She could be waking up when she is a little bit wet, there could be some noise (like a heater going on) that is waking her up, she could be too hot or too cold. She could just be waking up, noticing that she is alone and wants someone with her. It also could be nightmares. The best thing that I can tell you is to reassure her and try and get her back to sleep. Most babies have a period of restlessness and just seem to need time to figure out how to self soothe.
I gave my daughter tylenol the nights that she seemed to really be in some pain and I knew there was a tooth because I could feel it coming in and she slept like a dream.
Cheerios or something like that, sweet chinese rice crackers (similar to those nam nam things), pieces of small soft fruits, softened veggies, little cuts of fruit leather, she might be ready for those finger foods and biscuits at 9 months so just watch her with some at first and if she does okay then go for it! My daughter was through with baby food before we even began and did very well with stuff off of our plate way earlier than she should have.