Should i tell her to stop being insensitive and selfish, how?

She is being that way because she is still young and by doing that to you it makes her feel good about herself. If you feel the need to confront her go ahead and do it but then after that I would lose her number because she is not a true friend to you. I would not contact the guy either because if he likes her too and knowing that she is actually already taken that says a lot about him as a man/boyfriend material. There are plenty of other men out there that doesn't care if you are a single mother or not. A man should love/like you the way you are because when you have kid(s), you come as a package deal. You are right about the not trusting girls because that is exactly what and how she is acting, like a little girl instead of a woman.