family baby shower drama

I am 19 weeks and we just started looking to plan a date for a baby shower. My sister and mom want to plan it. The problem is my aunt is crazy and she and my sister don't speak to each other. My aunt started stuff at my wedding a few years back and my sister cut her out of her life. I don't want to hurt my aunts feelings, but I don't even know if she should be invited to the baby shower because I know she will start drama with my sister. It's not fair to my sister or the guests and it's not fair to me to have the extra stress! Is this wrong?