Prefix
A prefix used before father, mother, brother, sister, son, daughter, child, etc., to indicate that the person thus spoken of is not a blood relative, but is a relative by the marriage of a parent; as, a stepmother to X is the wife of the father of X, married by him after the death of the mother of X. See Stepchild, Stepdaughter, Stepson, etc.
Source: Webster's dictionaryHaving kids has been great for me. I have two beautiful step- kids, as well as my own new daughter. They've really helped me to keep my feet firmly on the ground, and life is good. I feel like I'm the luckiest guy here. Matt LeBlanc