The daughter got the sickness from her biological mother, not FL. FL doesn’t have any sickness so her baby won’t be either.
I think what @orange_cat was trying to say is maybe the dad is also a carrier of the “cancer genes” because (one can be a carrier without suffering from the disease/disorders.. i.e sickle cell) if it was solely “cancer genes” from the mom it Should have been the son that was sick because the mom will always provide the X chromosome and men could provide X or Y so,If the husband didn’t wasn’t a carrier of “cancer genes” as well it should be River that’s sick not Winter.
Zamn i learned something new today lol
Considering criss cross inheritance, the boy was supposed to get sick. Since it's the daughter who is sick, will the fl's secret baby be sick too?