You will also need to check licensing requirements - some app developers only allow their app to be installed on one device.
And, also best check the rules of Family Sharing as well - here is an excerpt (there is a lot more to that):
Family Sharing Rules: You can only belong to one Family at a time, and may join any Family no more than twice per year. You can change the Apple ID you associate with a Family no more than once every 90 days. All Family members must share the same Home Country. Not all Content, including In-App Purchases, subscriptions, and some previously acquired Apps, are eligible for Purchase Sharing. Apple Arcade and Apple News+ subscriptions are automatically enabled for Purchase Sharing. Subscriptions shared by a Family may be subject to Content usage
limitations on a per subscription basis.
From here (US terms):
https://www.apple.com/legal/internet-services/itunes/us/terms.html