Ruby (Dixon Hill)

Ruby was a holographic character from chapter 13 of the holonovel The Big Good-Bye who was one of Dixon Hill's "girlfriends."

When Jean-Luc Picard and Lily Sloane entered the holodeck on board the USS Enterprise to escape two Borg drones, Ruby approached Picard (believing him to be "Dixon Hill", a role he'd previously played), dancing with Sloane, and passionately kissed him.

Ruby left after Picard asked her to, adding that he'd meet up with her later. She advised him to "watch your caboose and dump the broad." (Star Trek: First Contact)

Ruby was played by Hillary Hayes.
According to the Star Trek Encyclopedia, 2nd ed., p. 422, the character was named after the wife of Star Trek: First Contact co-writer Ronald D. Moore.
In early drafts of the script, "Ruby" was the name of the character who would eventually become Lily Sloane.