For Heaven's sake stop mollycoddling this child. If she is nine, she should know the following: road drill, not to talk to strangers, her name, address and parents' and your phone numbers.
Tell her, what we all were told when going out on our own: if she is scared by anyone to go into the nearest shop and ask a woman for help. Or if by any strange chance there should be a policeman or woman in uniform, then that is the person to ask for help.
And if her parents are willing to let her walk home, then bite your tongue. She is their daughter, not yours, after all.
I presume the child will not be walking a mile or so along an unlit country lane in the dusk, will she?
A child of nine should be able to make her own way to and from school- I am all for letting children be children, but this does not mean treating nine or ten year olds like toddlers.