One of the actors has been behaving inappropriately around her.
He has made comments about her appearance (e.g. the size and shape of her body) that she was able to ignore at first.
However, the comments have escalated to the point that it is interfering with her ability to maintain composure on the set.
What is she doing about this? Nothing.
The actor is a friend of either the director or the producer, so she fears that if she was to complain that they would side with the man, and possibly replace her on the show.