Derick Trucks is a pretty good guitar player from a drummer dad.
If you are referring to Allman Bros. drummer Butch Trucks, Derick is Butch's nephew. maybe Butch's sibs are also drummers - that I don't know.
Rock Siblings.....
I thought Julian Lennon had potential but that didn't happen. Forget Sean. Jakob Dylan is good but certainly not Dylan good. Zak Starkey has surpassed his Dad in every way. I think Damian Tuff Gong Marley does Bob Marley justice. Theres a bunch more out there, the more obscure the better. Any observations?