We met Worf's father, mother, human brother, klingon brother, son (that gets me to 5), now if we include Worf's wife(s) either 6 or 7 depending how we count K'Ehleyr. Vs Data's 6. So I guess!
I'm trying to think of who else was shown other than Rom, Nog and his mother... He talked a lot about a cousin Galen. I don't recall ever seeing him, or any other family aside from those mentioned, tho.
Unless you mean his Klingon family from that time he got married.
What about Kirk? We see his Father and Mother in the Kelvin timeline. His brother along with wife and child in TOS and SNW. Despite them not marrying, I think that Carol Marcus and James Marcus still count as family. We also see Admiral Marcus, Carol's father. Also Kirk did briefly have another wife, Miramanee, and unborn child. They got stoned to death before the episode ended and maybe the unborn child doesn't count as seen.