Please look at how a 3 year old Bhakta, Krishna Sudham, is being trained up in Krishna Consciousness by the devotees in China.

“Yes, to be determined that the child will have its last birth into
ignorance is very good. It is true that one should become a parent only if he can
deliver his ward from the clutches of death. And that is possible only with
Krsna consciousness. This is a very great service for Krsna, to give all
opportunity for the child to be trained up in devotional service, and it is very
good that you are thinking very seriously on this.”

(Srila Prabhupada to Hamsaduta and Himavati, 3rd March, 1968)