Just treat her like your daughter and don't be afraid and walk on eggshells like I always did when my son got out of rehab. She'll be fine or she won't be fine regardless of what you do or say, so relax and just let life happen.
It helped me to try to get past the addiction and just talk about everyday stuff...conversations like I'd have with a friend or any family member.
Hope this goes well for both of you.
Hugs