i was wonering how do the kids there repopulate if they leave when there 16 i dont see any fat girls there so how do they still have kids O_o

According to the wiki it's a secret.

The stork drops them off

or or santa brings them cause the girs asked him

I would imagine they take in orphans. The wasteland probably results in a lot of orphans.

That's what I think, too. Lucy was born in Lamplight, but I think she's the exception to the rule.

Truth be told, most of the Lamplighters look far less than their stated age. For instance, Knock-knock is supposed to be 14, but her outfit makes it obvious she's flat as a board. And Joseph, supposedly 15, looks about 12. And there's a logical reason for this: since the kids live primarily on pondscum and fungus, they're undoubtedly endlessly fighting all sorts of deficiency diseases. That's why Dr. Lucy needs Buffout from you. In any case, in a malnourished society, the age of puberty is much later than it is when the people are healthy. So truth be told, I don't think most opf the Lamplighters could reproduce even if they tried to.

Kids just get dropped off by a neutral-to-good advlt, or they escape and find their way there themselves.
That's how they, uh, 'repopulate'.

Right. Just as there's no law enforcement outside individual settlements, there's no foster care system or orphanages. A kid who's lost his or her parents can either be taken in by someone else (like Maggie), look after themselves (like Harden), or find their way to Little Lamplight, which is sort of like an orphanage except it lacks a staff. If they don't do one of these things, they'll likely wind up harmed or exploited. All four of these things can happen to Bryan Wilks.

I'm actually working on a fic called "Lamplighters' Fate", which is set a few months after Project Purity goes online. In it, the fungus that the kids eat can't survive in non-irradiated water, so the Lamplighters have to leave their home. The story actually touches on TH2010's original question, and more.

I think the sinister scav teams go out at night and steal babies from their cribs to repopulate.