Can I see who has watched what from my shared libraries?

I have 6 libraries that are shared with various family members. But is there a log of what each user has watched of mine?

Try installing Tautulli (formerly PlexPy).

Not within Plex directly.
But there is a great software for this PlexPy

PlexPy looks great.

I also put together a monitoring “who is watching” that notifies you in realtime (desktop and/or email). Check it out plex-watcher.