As Steve Urkel's scenes grew in importance on Family Matters, Judy Winslow's storyline started being swept under the rug. That, coupled with the fact that Jamie Foxxworth, the actress who played her, wanted a raise, made the producers axe her from the show entirely in season four. Later in the series, the Winslow parents referred to their two (as opposed to three) kids—yet another case of the Chuck Cunningham Syndrome.
Much like Judy Winslow, Foxxworth's career seemed to be grounded for life and locked up in the attic like Cinderella. Except when she reemerged in public, she wasn't a princess—she was a porn star named Crave.