sly smiling

I have a friend or I should call her a classmate. She always give me a sly smile when I meet her. I wonder why. To me, she looks friendly and generous to people. I thought it is so until I work with her for a project. She has two faces. One is the role model student with good behavior. The other one is a jealous and likes gossiping monster. I really do not enjoy working with her but I had no other choices. Everyone might meet this kind of people once in a while in their life. So, how to cope with them. Just do your own work and try not to say anything bad in front of them. Wish you all good luck.