Since players continue to build their Steam libraries through a single account, family members in the same household must access that Steam account from the same computer. To help make Family Sharing a simpler process, Steam users can now authorize up to 10 different computers to access their library of games.
If your family member or friend wants to access your Steam account from their own computer, the most recent update to the Steam client beta lets Steam users authorize other machines at any time. The authorization of both borrower's Steam accounts and computer reduces risks of VAC and other in-game bans.
Users participating in the Steam client beta can further clarify any questions through the Family Sharing FAQ.