New iphone

my daughter got a new iPhone 6s for Christmas. When I originally started it up I used my Apple ID. When I realized that she was getting my messages and calls I got her a new email for her own Apple ID. I thought I had reset it back to the factory settings up it must not of. It’s still under my name but her new email. It changed the email on My own phone and computer. And now I can’t get it to change back to my email for my phone. And all my contacts are still on my daughters phone.