Take what your sister says on board. You have to be calm but firm in your approach. I suppose there is a time for faith and a time not for it. Telling someone about faith, constantly, is a bad idea. Your sister wants things for you, and wishes you all the best. How you sort this annoyance out is up to you. You just have to be honest, and tell your sister to stop talking about church. Calm but firm in your response is best. You dont want to be too rude, it could damage your relationship with her. All the best.