Babyshower? HELP

AITA? I wanted to throw my own babyshower, but my mother in law and step mom are having a fit because it is “unheard of”. A little back ground my sister and I are 13 weeks apart and will be having our showers just a couple months apart. They suggested I have a small shower and re-use my sisters decorations. She is having a girl & I am having a boy. I told them if they wanted to help financially it would be more than appreciated but not necessary & I wouldn’t mind planning my shower with the assistance of my sister in law. Should I give in and let them throw my shower or should I continue with my plans and throw my own shower?