How to prove to my friend that I'm not selfish?

my friend harriet she keeps saying im selfish but I dont think I am but I just dont know how to proof to her im not when she comes over I always ask her if shes hungry what she wants to do all ways guest first so how can I show her or tell her im not selfish ...well maybe I am

Well, maybe it's that shes used to getting her way, so if you don't agree then she thinks your wrong and shes right. Maybe she is actually the on who is selfish.