You can't sync your entire iCloud Photo Library with your family, but you can still share images with them.
While iCloud Photo Library supports syncing your photos, videos, and albums across your own personal devices, it doesn't offer an option to sync everything to a family member's device: After all, do you really want to share every photo or video you've ever taken with your family? Probably not.
As such, if you have Family Sharing enabled, you'll still have your own Photos library. But that doesn't mean you can't still share images with each other easily. Here are three options I've been using to keep my family in the loop.