Is this girl coming onto me?

So I've liked this girl for about a month or two, and we have a class together. I think in the last week, we've really started to become friends. In gym class whenever I would be struggling with something, she'd say "C'mon I_Fisted_Blastoise you can do it!" From time to time in gym class, I would see her looking at me from a distance, however this doesn't happen very often. Yesterday, I saw her after school and when I walked up to start a conversation, she turned around and immediately smiled and said hey. She started talking about some impressive thing that I did during gym class to her friend that was walking with her. She then started talking about why she was still at school even though dismissal was an hour ago. When I had to leave i said bye and she smiled and said bye in an oddly soft tone. Today, I wasn't able to talk to her much, so when I saw her at the end of the day I said hey and she said hi back. She said it in a soft tone much like the day before. However, my friend kept walking behind her after I walked away and overheard her talking to her friend. Her friend said "Aww I_Fisted_Blastoise is so cute" and the girl I like said "Yeah he's really nice." My question is if she is coming onto me?