Is it possible to only share specific games through Steam Family Sharing?
Solution 1:
To an extent, yes and no.
As the Steam Family Sharing FAQ says,
Can I share specific games, or do I have to share my whole library?
Libraries are shared and borrowed in their entirety.
That's the "no" part. However technically there is a way to enable only selected games for accounts you're sharing with. You can do this by using Family Options. Here's how.
First, login to the account you want to be used (the account you want the game[s] to be shared with) to unlock the library.
Secondly, then with that account logged in, activate the Family Options with a set PIN.
Then whenever you want to set a suitable game for that person, log yourself into their Steam client, unlock Family Mode with the PIN, and set the new game to " Family Games" and then lock the account again.