No matter how ya slice it, if you get married, whether you gave birth to them or not, you have kids. We have a simple rule in my house:
NO ONE is a step above or below anyone else
NO ONE is half of a person, we all have two arms, two legs and full hearts
NO ONE is allowed to refer to anyone else as "half or step" anything
WE ARE ALL a family, no matter what.
It used to REALLY hurt my feelings when I was treated badly by my fathers mother. I say this, because he is not my biological father. He is my daddy. He raised me. He changed my diapers and bought me my first bicycle. He taught me to fish and drive a car. HE IS MY DADDY. And to her, I was just a stepgrandchild. Not worth of being on her level, just a step below it. The funny thing is, not a single time did he treat me like anything other than his daughter. And now that he is in very poor health, he has made it adamently clear to my mother that NO ONE is allowed to list me as "step-daughter" in his obit. Which fills my heart to the brim.
I feel that way about my husband's first batch of children. They have a wonderful mother, but I am their Gina. I am the one that they can come to when there is no one else, those things that are too much to tell your parents. However, I am their parents. You will not hear or read me refer to them as step children, because they are my children. Whether or not you give birth to a person does not make you a parent. It is love and time and devotion to that small being that creates the parenting bond. When their mother's second husband died, they were simply listed as children, which is exactly where the entire brood of us fits in. We went to that funeral, and cried as if a member of our own family had passed, because we were all a family together, even if the two of them could not be married.
So, I just wanted to put out there for all of the world to understand my view. I am not trying to replace a mother, I am just an additional one. How many people in life are lucky enough to get more than one set of good parents? I hope that at least half of my children are in the numbers of those who are.