how did the parents brought up their kids in lilliput?

For a start;

"........their tenderness towards their young proceeds from the like natural principle: for which reason they will never allow that a child is under any obligation to his father for begetting him, or to his mother for bringing him into the world; which, considering the miseries of human life, was neither a benefit in itself, nor intended so by his parents, whose thoughts, in their love encounters, were otherwise employed. Upon these, and the like reasonings, their opinion is, that parents are the last of all others to be trusted with the education of their own children; and therefore they have in every town public nurseries, where all parents, except cottagers and labourers, are obliged to send their infants of both sexes to be reared and educated, when they come to the age of twenty moons, at which time they are supposed to have some rudiments of docility. These schools are of several kinds, suited to different qualities, and both sexes. They have certain professors well skilled in preparing children for such a condition of life as befits the rank of their parents, and their own capacities, as well as inclinations."