When should my baby shower be?

We are starting to plan a bit of my shower starting with the venue (yes I’m helping the planning- I wanted to!) but idk when the date should be... my due date is July 6th so I was thinking the end of May, but my sister in law is due at the end of May. She has a problem with her ovaries and cervix so her doctors don’t want her to go into labor on her own and are thinking she’ll have a c section at the start of May.

Any suggestions of what we should do?