There is a listed bestow curse that automatically ages a creature to the next age category.

I could see a bestow curse or perhaps greater bestow curse preventing a creature from growing/aging (Obviously not extending a creature's lifespan). Might have some other drawbacks like it still accumulates physical ability damage from aging and their form getting a bit more withered to prevent humans from using it on themselves while in their prime.

But for a wyrmling using it for a couple years shouldn't have any problems.