Everyone has an adoptive mother. You know who yours is. If she doesn't occur to you right away, all you have to do is think back a little.
To help jog your memory I'll give some examples, starting with my own "adoptive" mother. She is the mother of my childhood best friend, with whom I'm still in close contact. Whenever I stayed at Becky's house, I felt how her mother took me in. She was the mother who kept lots of pets and porcelain dolls. Who not only had German roots, like me, but had a German accent. She also made food for me and told me to be careful and play nice. When she'd come in before we went to sleep, she added me to the list of family in her prayers. She even hugged me and told me she loved me.
I grew up with Ilsa, and she's still in my life. Adoptive mothers always remain in your life, even if it's more in idea and influence than physical presence. When American students go to college and join a Greek club, they gain a house mother. When they travel overseas, they may stay with a host family and have a host mother who takes care of them like her own. I have a Korean friend who came to America and got adopted by an older woman he calls "Grandma." Grandma invited him over for Thanksgiving and Christmas dinners, read stories to his son, and sometimes called him just to see how he was doing.
Our adoptive mothers in the nonlegal sense can be very close. My neighbor was the primary guardian, though not legally, of her grandson. The boy's birth mother visited and sometimes took him on weekends, but the arrangement was much like an open adoption, with the birth mother choosing not to be a parent, and another mother adopting that role. The birth mother stayed active to some extent in her son's life. He knew she was a different kind of mom, but she was his mom, too.
I knew of a man who was a single father since his sons were small. Their mother called them only on their birthdays and some holidays. The boys were all very well balanced, kind, and compassionate. I knew that single parents raised great people all the time, but I had to wonder how these boys flourished like they did without a mother. Then one day, one of them got a call from a woman and laughed and talked easily on the phone for an hour. I thought it was his girlfriend. "That was Renee," he told me later. "She's like my Mom." He didn't need to say more. This woman, a family friend who no longer had contact with his father, had remained a constant in the boys' lives and looked out for them "like a mom."
"Mom" and "mom-like" are very similar, if not practically the same. Different moms do different things, but most share certain qualities like nurturing, caregiving, nursing, feeding, clothing, protecting, guiding, encouraging, and loving. In fact, the only difference between "Mom" and "mom-like" is that one is a name given to a particular person, and the other is a title given to everyone else like her .
In some cultures, past and present, a child can literally choose her mother from a host of older female relatives. When they are all part of a close, safe community, this works. In some cultures, even the word for "mother" and the word for "aunt" are the same. A child may get along better with his aunt, and his aunt better with him than with her birth child. The aunt and nephew would then adopt one another.
In Mexico, grandmothers are mom-like. They take active, mom-like roles in their grandchildren's lives, and often live in the same house. They may not be called "Mom," but to some extent they share Mom's duties. Some moms probably wouldn't know what to do without help from their own mothers.
You don't even have to be female to be mom-like. Some children are raised by two men, one of whom is more mom-like. Some men are stay-at-home dads. They are fathers, but they are also mom-like. Remember that single father of three boys? He gets a Mother's Day card every year.
We all have adoptive mothers. Because everyone has one, there is no reason for one to feel jealous or threatened by another. Would the single dad's sons have been better off without a friend who chose to be "like a mom" to them? Would it be better to keep Grandma or Aunt confined to a strictly non-mom-like role, and how exactly would you do that? Would you prefer your 18-year-old daughter studying overseas to stay with a group of teenage friends or with a family and a host mom looking out for her?
Figured out yet who your adoptive mom is? Think about her. Would you have wanted her to care less for you, or be less mom-like? How would it have affected you then, and how would you be different now?
Children need to know who they can always go to when they need "Mom," capital "M." In addition, they need mom-like people in their lives. These can be step moms, birth moms, grandmas, aunts, dads, host moms, house moms, and friend's moms. Mom-like people work together all the time. It's nothing new. In fact, it's the way things have always been done.