Maybe "ruin" is too harsh of a word, but watered down or soften. Let me try to explain. Some of the comments (https://www.datalounge.com/thread/19290146-why-were-susan-sullivan-and-wendy-schaal-thrown-off-it-s-a-living-) that I've read (https://web.archive.org/web/20061031150705/http://www.jumptheshark.com/i/itsaliving.htm) is that when It's a Living was first revived for the syndication market in 1985, Cassie went from being this pushy, man-hungry woman to more of the "team-mom" (https://tvtropes.org/pmwiki/pmwiki.php/Main/TeamMom) (Nancy was more of an antagonist/mean boss (https://tvtropes.org/pmwiki/pmwiki.php/Main/MeanBoss) type of figure), which in theory, should've been Jan's role since she actually was a mom.

The funny thing is that they may have also derailed Jan's character when they had her marry Larry Dallas;). Before (in the ABC episodes), wasn't she going to school to be a lawyer? It seemed like that sort of ambition and sense of liberation was dropped come Season 3 and onward.