Not related to anyone famous.
But my mom and dad were hippies in SF in the 60s and got to know many people! I visited Paul Kantner's home when I was little and played with his daughter...she had one of those ride-on inchworm/caterpillar things and I thought it was so cool. Re-met her backstage at a concert as a teen, a few years before she became a VJ...we were backstage b/c of my mom's friendship with Paul.
Mom met Jimi Hendrix.
Mom and dad were at a party when the hosts got a call that Paul McCartney was on his way. Sadly, instead of staying, my dad made them leave, and they didn't meet him. Dad says that night changed everything in their relationship, and if he could go back to change it, he would.
They knew some of the guys that later became the Grateful Dead...my mom enjoyed their music at the time, but said that the only way you can really enjoy a 20 minute long guitar solo is if you're smokin' something interesting...otherwise, forget about it. I agree, and it was really annoying that I had "latter day" deadheads as my next door neighbors in college! That's been done, dudes, get over it.
Mom had a long involved story about how my dad handed over keys, after being specifically told NOT to do so, to Neal Cassady, who was known for destroying cars. End of the story, yep, car was found, in a ditch, destroyed. Silly dad.
Went to college with the son of a very famous (now dead) actor/producer guy and became good friends with him (the son). He has the most amazing people on his FB page, and they are actually friends, since they all grew up together in the weird world of having a famous parent or two.