Don't fall into the trap of thinking that an apology from your mother has magical powers and will miraculously make you feel better. Let me assure you from my own experience, it won't. In fact, when my mother finally recognized that she had parentified me and said sorry, it made me feel worse.
When I was in my 30's, my mother and I were on a car trip, listening to a psychologist's radio show. A caller phoned in and discussed being parentified by her mother. After listening to the call, my mother turned to me and apologized for using me as her therapist during my teen years when she and my dad were having marital problems.
Since she never admits to any wrongdoing and never apologizes, it was nothing short of a miracle. Yet, it left me feeling dissatisfied as if my experiences as a parentified child were being trivialized by her. Because she didn't acknowledge the long-term impact of the parentification and the depth of hurt it caused me, her words seemed empty. I had longed for that moment and was left thinking: Is that all there is?
Moreover, an apology from a parent means nothing unless they've changed their behavior. If I were to allow it, there's no doubt in my mind that my mom would still be parentifying me today. After all, she created that dynamic between us for her benefit. She groomed me to be the child who would listen to her problems, provide support, and give counsel. As long as I played that role, I was rewarded with her time, attention, and praise. When, as an adult, I made a conscious decision to stop doing it, I was no longer of use to her and got replaced with my brother.
Don't think for one minute that you need an apology from your mother as some sort of validation that you were parentified. Don't turn over that power to your mom. You know what happened to you and that's all that matters.
If she were to say “I'm sorry,” it wouldn't change a thing. You'd still have to move forward with your life and nurture yourself in ways that your mom never did. Bishop T.D. Jakes says: “Be what you are missing to yourself.” You didn't get the mothering you needed as a child so be kind, loving, and patient with yourself now.