That's it. I also think the realism touch is lacking in this story, and it's just too ideal to be true. Well maybe it's just a manga, but reader, especially the young one, also need the truth of what'll happen if something like that indeed happen right? No matter what, that's just wrong and it's risky for a child that young to give birth, also how a child to even have the idea to play with their 'thing' is also something to repent about. The author shouldnt just potrait the part how it's touching but also how it is actually wrong and what's the consequence of doing it and how to prevent for future case.
So sorry for my rambling i'm just being kinda emotional.
This is DEFINITELY one of those "best case scenarios". I mean, a girl her age would probably die due to the trauma of childbirth and if she didn't she'd probably be constantly harrassed by the neighborhood for being a mother at her age.