Is she being genuine or petty?

When I told everyone about me getting a job interview, they cheered except this one girl’s response was that someone she knew had that job and didn’t like it. It made me question if I should go through with it or not.

I also remember also stating once that I wanted to work in a movie theatre (I love movies) and she said she worked in one and that wasn’t a good job.

This girl is somewhat my friend but mainly just around because she’s friends with my friends. Me and her are also coworkers at my current job.