When Melinda meets Jason's mother, she notices a bench that appears to have metal plaque in the wide shot. When the camera zooms in the plaque appears to be a piece of paper.
Melinda remarks that Sybil is just one year older than Fran was when she had Jason. This would make Sybil 18 years old, which is impossible since Fran didn't meet Sybil's father until after she gave Jason up for adoption and Jason said he would have been 18 this week, which means Sybil, his younger half sister, can't possibly be 18.
Jason mentions having an adoptive father multiple times to Melinda, but they are never seen or mentioned by Jason's adoptive mother.