In chapters 31 and 32 of "Hard-Boiled Cop and Dolphin", a preadolescent girl is possessed by Poseidon, who ages her up a bit so he can more effectively use her powers. In dialogue, he says he was only able to get her from "10 to 12" but apparently she'll have quite a growth spurt, because her clothes get very tight.

Poseidon overdoes, and the girl returns to her normal age. As of 2/28/21, these chapters are free on the official Shonen Jump website.