Looking at the entry for Kay Cappuccio, my visceral reaction was, "Oh, honey!", which instantly made me think of Katy Perry's guest turn in Season 6 of HIMYM. As far as I can see these two characters could practically be twins, or at least identical cousins. So I'd be curious to hear who else other people think could be an offshoot of the same family tree as guest characters on other shows.
Another suggestion, to get the ball rolling, might be Serena Kaye, from Eye of the Beholder, as the ultimate great-grandmother of Jennifer Hettrick's Vash on Star Trek (TNG).