This unfortunate but I know people like that to. The give and take relationship is more take than give. They take you for granted and they know you when they want something. It is unfortunate though because you want a healthy friendship with her. What she wants is what I call a fair weather friend. She is your friend sometimes but not all the time. This is not a friendship that you can benefit from. It may have been at one time but not anymore. You have to consider something in order to not grieve the friendship as much: Is this friendship what you want in terms of a positive friendship. No it isn't. You need to eliminate this friendship because it isn't healthy and it will never be. When you accept that then you can let this go. When you accept that.
If this has been helpful press accept