Why is villager breeding failing in a village?

Villagers are annoying. They use some odd methods of pathfinding that don’t always work.

1. Take 3 villagers FAR away from the original village
2. Build up a villager breeder (Tango Tek makes a good one on that)
3. Done!

I honestly would not use the original village

If you don't want to use the villager breeders, give each villager exactly 32 carrots (or bread and so on). Make sure they have at least 4 beds within the same room. (you can change their bed, but that will help with the pathfinding issue)

Hope this helps!

The beds might not be close enough, or there might not be enough free space above them for the baby to jump.

[They] can produce a baby only if they have their own beds plus an available bed for the baby, and the beds have two empty blocks above them (there needs to be room for the baby to jump on the bed). If the population cap is met, or the beds are obstructed, angry particles appear above their heads (along with the heart particles), preventing them from mating.

Minecraft Gamepedia