What the hell show was this?

Was at my mother-in-law's on Sunday and this 70's sci-fi show was on...what the hell was it (never mind the obvious "why was this on?")?  My parents never divorced so who knows what else I missed.  Anyway:

This girl was always showing up in the 70's, such as on Brady Bunch
and I think she was one of the earliest (if not the first) to voice-act
Lucy in Peanuts specials.