The new mom, 24, who gave birth
to son Luca Cruz Comrie on Tuesday, is sharing her joy with the world, calling her little one, "the most wonderful, sweet, adorable baby."
"Wow, I can't believe I have a baby!" she Tweeted
on Friday. "Thank you for all the messages and well wishes. I love you all so much."
Duff announced in August
that she was expecting her first child, saying that she and hubby Mike Comrie were, "ready to start this new chapter in our lives."
She described the experience of being pregnant as, "Kind of like a little alien has taken over your body. You just don’t quite feel normal."