Fed up with her

Looking back I think I involved my sitter too much in my marriage break up. I confided in her a lot and cried many a time on her. She was a great support. All that seemed to change when I met a new partner after a month of being separated.It wasn't planned but felt very right. My sitters behaviour changed to being very distant. When I asked her what was wrong she admitted she was concerned as it was so quick and we spoke and sorted it out.

About a month ago after 6 months of dating, I introduced my kid to my new partner, again my sitter seemed very distant and couldn't look me in the eye. I texted her yesterday asking if there was anything she wanted to talk about as she is so eager to get out the house and cant look me in the eye and she said she doesn't want to be seen as the bad guy but has concerns. That she knows she is not family but can't help how she feels.
I feel annoyed now. She is wonderful with my kid but I am not doing anything wrong. Thoughts?