irritated at sisters input on circumsicion

My older sister who isn't married and never wants kids asked me if I will circumsice my son when he's born. I believe to each their own. I told her my husband and I decided that we would and she has been going off on me for the past week feeling me not to do it. That I'm ruining his body etc. She's trying to get me to change my mind and my husband and I are set in our decision. Anyone else deal with people telling you how to raise your child? She also tells me not to get the epidural which I decided that I want if it all works out. Just feeling frustrated