Eh, I'm sure they all have moments when they just need a moment away from the Brady-mania. I give her a break. I was thinking that Florence would probably have done this show, but Bob Reed wouldn't have touched it with a thirty-foot pole. Ann B. Davis may have done a one episode guest spot.
And I echo the comments wondering who would want this place when they are done. It's not like the Brady home was a more classic 50s/early to mid 60s mid-century design. It was a fairly ugly late 60s/early 70s look that even when new, doesn't look great.
Just looking at IMDB, she appeared on five Love Boat episodes, and six episodes of Fantasy Island. I would say she did several guest spots on each show, but given the number of episodes each of those shows produced, I don't think I would call her a regular.