What in astrology tells what someone would be like as a parent? The fifth house?
I think the 4th house tells more about what sort of mothering role you play. For example a debilitated first lord, Saturn, in the 4th house tells that mothering is extremely important to the person, but they lack patience and steadiness in how they nurture. Yet the act of nurturing is extremely dear to the person.
I think the 10th house tells what sort of fathering role you play. For example Jupiter in the 10th house shows that the person likes to be a philosophical and moral guide to the children, and help them grow on their own.
Birth charts are like combination locks, you need more than one number to line up before the lock opens. So in addition you look of course to the rulers of the houses 4, 10 and 5. And also look at the planets Moon (mothering/nurturing), Sun (fathering/guiding) and Mercury (children).