No, it is not correct to assume that the probability would favor their next child being a boy. The gender of a child is determined by the genetic combination of the parents, and each child has a 50% chance of being either a boy or a girl regardless of the gender of their siblings. The previous children being all girls does not have any impact on the probability of the next child being a boy. Each child is an independent event, and the gender of one child does not influence the gender of the next child.
