J.M.
Are they licensed?
What are their disciplining techniques?
Ask about the other kids in their care.
Go and visit during the day when they have children there to see the interaction. Do not ask alot of questions this day just observe her with your child and the others in her care.
Ask for references and use them, make sure they are clients or former clients.
Ask what she would do in an emergency, if someone gets hurt or if there is a fire.
She should have well prepared answers for these questions.
I hope this helps!
J.