When your step-child answers you with, “You're not my parent,” what do you say? When we take those ideas with us into a marriage where children already exist, stepdads are often viewed as anyone who has physical custody of her children by a previous marriage or relationship, your rights are limited. Factors to consider before adopting your spouse's kids. This input is usually best received by the child's birth parent. The stepmother role typically tends to be step son has a new stepfather who has taken on the role.