I'm not sure why Jaycee would need to think of her stepdad as her own dad unless her mom gets back together with him or just at family get togethers with her half sister. She only knew him for 3 years and if the couple divorces, that could be even more confusing. Jaycee may want to know her real dad after the big farce she and her girls were subjected to for so many years. She may even want to make sure he's her real dad before getting involved with some man.