I just checked - looks like he and Ruth are still alive and married...
I saw Zappa with Flo and Eddie (Turtles) right after Chunga was released, at the Felt Forum, just before the Live at the Fillmore show. Ruth Underwood was also with him for that show. I’ve seen Dweezil and his band, they do a great job recreating his music.
Thanks, this was fun.