Regarding Champion ages, do they work the same as in RL or not?

Since Runeterra's a world of magic and all, I think that it would make a lot of sense if aging worked differently in Runeterra than it does in real life.

For instance, Annie's a little girl who looks seven or eight, but could be something like twelve or thirteen (no, she's not legal age yet, you pedos). Lux looks like a teenager, but actually be in her mid-twenties to early-thirties. Katarina, who looks mid-twenties, could be in her forties. The list goes on.

I don't think there's a real downside to this, but I could be wrong. Any thoughts?