Martin Sheen’s bio page on Wikipedia says his mom’s name was Mary Ann Phelan, and that she came from a small village in County Tipperary. Not coincidentally per this post, my own grandma’s name was Phelan and she also came from a small village in Tipperary, albeit slightly farther south than Martin’s mom’s village.
While I feel bad for Charlie these days, I’ll claim them as distant celebrity family. This is particularly useful after the longstanding notion that Buffalo Bill Cody was a relative was sadly debunked last year. Still bitter about that one.