I think we all agree that Fabigail is likely Jack's daughter but probably not Jennifer's and nobody is going to check. I've seen lots of speculation that she's Gwen on a grift, but I can't see Ron resisting showing another Theresa and Gwen swap, nor him recasting his beloved Emily O'Brien (Gwen). If she is not actually Abby, but doesn't know it, let me throw out another possibility. Back in August 1988 Melissa dumped Jack at the alter and blew town, going on their honeymoon alone. She returned in early 1990, angrier at Jack than even when she left. If she was pregnant and had dumped his kid somewhere this would actually make sense. And Fabigail would have ties to the Hortons and Johnsons. Anyhow just a thought because I hate Gwen.