Her parents are never revealed throughout the entire show since she is staying at her uncle’s house, so we don’t really know what they look like. Her uncle now has gray hair but in flashbacks throughout the show he is seen with brown hair, her uncle’s brother has brown hair as well. Mabel also has a twin brother named Dipper, and he has brown hair just like his sister. From her uncle’s we can see that most of her family has brown hair, so we can guess that her parents do as well. The punnett squares for each trait were created by looking at the traits of both parents, one parent having a more dominant trait than the other in each punnett square. For example, Spongebob has light yellow hair which would be recessive compared to Mabel’s brown hair because neither of Spongebob’s parents show that they have yellow hair but they could be a carrier. And Mabel’s uncles had brown hair, so her parents most likely also had brown hair, which would make her brown hair more dominant to SpongeBob’s light yellow hair. For the skin color, I just compared Mabel’s white skin to SpongeBob’s yellow spongy skin and since Mabel is American and SpongeBob is Polynesian, the baby is most likely to be