I believe that Carl was in every show, but was Laura? I think so, but can't confirm. I could imagine how Jo Marie felt in the end, since this series was created for her and Steve Urkel basically took over the entire series. In the last season before she quit for good there are several episodes that she isn't in at all and by and large her roles in most of the others are relatively minor. Eddie is absent from some episodes as well, but I guess the producers figured that the glue of the series was Carl and Steve and I guess Laura.

In episode 117-A Camping We Will Go, Laura does not appear, it is also the first episode that does not feature Harriet, this episode only focuses on Steve, Carl, Waldo, and Eddie. Laura appeared in every other episode.

I too can imagine how JoMarie Payton felt. The show was her spinoff and as time went on her role got smaller and smaller. In season 9, there were a lot of episodes she did not appear in I think because she had already made up her mind that she was going to quit anyway so at that point I don't think she even wanted to appear in a lot of episodes because the producers and writers kept turning down her family-themed ideas.

Wow so Carl was the only character in every single episode.

Your'e forgetting about another episode Laura was not in. The one from Season 2 (the last episode which featured Eddies friend Rodney) when that guy at the bar tricked Eddie into playing pool and beat him out of $250, and they came back and Urkel played the guy in pool and was winning and the guy broke his glasses. I don't think Laura was in that one either.

If she wasn't in that episode, I'm sure TVTome would have pointed that out.