Heretics might respond by claiming i) Jesus didn't baptise any children
and ii) the thief on the cross wasn't baptized.

To which we simply answer: baptism was not instituted until the Resurrection! We could not be baptised i.e. become partakers of Christ's death and Resurrection, until He Himself had died and been resurrected!

danmaynes Why do Catholics baptize infants? Why not wait until the child can accept Jesus personally?