Who gets to decide whether a woman is “qualified” to be a mom. Also who decides when a mother is spread too thin? Large families are such a blessing in which all members get the opportunity to learn the virtues especially love, patience, and sharing. NFP is the way to go if there is grave reason to delay children as it works with nature and not against it.
Contraception has been a disaster as the divorce rates, out of wedlock birth rates, single motherhood (with the new boyfriend abusing the children), pornography, shacking up , abortion (which needs to be legal for contraception to work as it is the backup) etc have shown. Contraception is as vital as throwing up is to people suffering with bulimia.