I wish I could get a trainer, but be that as it may, if I had one and she was like that, I would get another.
Sounds like she has made friends with you and now is (maybe not intentionally) taking advantage of your kindness and friendship and not taking her job as seriously.

For some reason you can't seem to pay someone and still be friends with them. Or be someone's boss and still be friends with them. Most people, (not all) cannot keep the two seperate.