I adopted my daughter, Rachel, when she was a newborn. Rachel was about two and a half when I told she was adopted. That was when she was asking where babies come from and I explained that babies grow in their birth mother's womb. I told her that her birth parents loved her very much and wanted her to have the best life possible - so they gave her to me, for me to be her mom. I haven't explained the specific reasons they had for placing her for adoption, that will happen when she's old enough to understand. I think it's important to be honest with her as early as possible. I never want her to feel shame or surprise about her adoption.
I also believe that I am her real mother. And that her birth parents are real parents too. Right now I use words like birth mom and birth dad, and just mom, mama or mommy for me. Nature and nurture both play a role. Right now, I think nurture plays more of a role. Rachel takes after me in many ways already and she's only four.
My experience with her has been amazing. She's the best part of my life.