Yes. I think only one, though, Diana Hubbard (not sure if she still has that last name), who is his daughter. My understanding, though, is that she's disaffected, but Miscavige controls her through Hubbard's estate's will, and the Church trots her out every once in a while at an event, but for the most part, she is not around much (probably has to do with her inheritance).
Quentin was a top auditor, but suicided. Nibs (LRH jr.) was a research auditor, and credited with a lot of early work on the Bridge, but became disaffected later, and now won't talk about it (probably as a result of numerous lawsuits).
I think LRon was an only child.