No article about the would be complete without addressing the community standards. ConcernedApe (Eric Barone) has stated he has no interest in adding child marriage to the vanilla game. However, he supports modding as long as it doesn't violate platform rules.
For those who want more interaction without marriage or adoption, several "lore-friendly" mods exist to flesh out her story: Jas Marriage Mod (removed) - Chucklefish Forums stardew valley jas marriage mod top