Hello swandy and welcome to Apple Support Communities.
I see you have a question about Family Sharing and what exact info is shared amongst members of the family group.
Set up Family Sharing - Apple Support
At this time, there is only one set of sharing permissions per group. When you set up a family group, all members will have access to items such as the Family album in Photos and the Family calendar in the Calendars app.
However if the member of the family group is not an adult, you can turn on a feature called Ask To Buy which would alert you anytime that family group member tries to make a purchase.
Request and make purchases with Ask to Buy - Apple Support
"The family organizer can turn on Ask to Buy for any family member who isn't an adult. It's on by default for any children under 13, and you'll be asked to set up Ask to Buy when inviting anyone under 18 to your family group."
Cheers.