I think you can also do that in VV2. I get a lot of master doctors early that way.

Woa that is awesome I did not know there is a potion that makes somebody sick.....

You can use the kids in VV1 too whenever there is an event that causes an epidemic.

There is a potion that makes villagers sick. And luckily, children can heal at 2.

Woa that is lucky lol because without a doctor no one could hel your village

In VV2

I also used this technique to make master doctors, but I think it is strange that anyone can heal other people, even children.

I don't know about 2 year olds, but I think that some young children can understand bed-rest, blowing your nose, and cough syrup. All we see in the game is them waving their arms at the sick villager... for all we know the kid is making faces them and making the sick villager laugh themselves to healthy.