I think if I were you I'd want to bring this up with her and get some clarification on what it is she did mean. Tell her how you received her comment and how strange you thought it to be... maybe it was just an errant comment, or yes - perhaps she is depressed, or has been. I'd really want to know what it is she intended to communicate - or if like some other poster have suggested, she was just trying to 'push your buttons' or provoke a reaction. One never knows with Ts!