I have met many celibates, both men and women, lay, religious or ordained, who were incomparably better with children of all ages than many parents who raised multiple children. In fact, I know many parents who should have been barred from having any children, given the way they treated and raised them.
People can become wholesome human beings or a crooks, regardless the form of life they have chosen.
As to a 3 or 4 year old being "fallen, or unclean," first you need to recognise that human beings exist both in their individual and corporate identities. One cannot be divorced from the other. Augustine's idea of original sin (never considered a personal sin), despite all its imperfections, refers to a very real aspect of condition: a child being raised (and so, formed) in an environment marked by sinful (broken) human relationships.