@Kevadu The main story has not been subtle at all at that future implication. She's the number 1 most likely for that to happen to according to their fellow students in the main story after all.
@Kevadu specifically at the start of Chapter 147 it's implied that the famous doctor is the grandfather of Kashiwagi's boyfriend, and he mentions that both he and his son each had their first child at 17, so this is a reference to that "family curse"