When I invite my adult children to share my family iCloud storage account does everyone continue to pay for there own purchases and can share those purchases with the family Group or am I as the organizer of the family group now responsible to pay for everyone’s personal purchases?
I believe that you can share an iCloud storage plan without sharing purchases.
To share iCloud storage, see instructions in Share iCloud+ with your family - Apple Support
Note that the first step to doing that is to set up Family Sharing as described in Set up Family Sharing - Apple Support
but there is no mention of any requirement to turn on purchase sharing. Purchase sharing is described in How to share purchases with your family - Apple Support
Sharing iCloud storage with family
