Q: I want to control purchases on sharing group even if they are adults

Hello gr8tbald1,

Welcome to the Apple Support Communities! At this time, the Ask to Buy feature of Family Sharing is not available for adults. However, the feature can be used for anyone within the family that is younger than 18 (in the U.S., age varies by country). For more information please refer to the following resource:

Request and make purchases with Ask to Buy - Apple Support

http://support.apple.com/en-us/HT201089

Ask to Buy is a feature of Family Sharing, and the family organizer can turn on Ask to Buy for any family member who isn't an adult.

Thanks,

Matt M.