In Chicago this gets tricky. I would say it depends on your neighborhood. Are you in Englewood or North Lawndale? or are you in Lincoln Square or Lake View?
We live near Humboldt Park. My daughter is SUPER responsible and there is NO WAY I would let walk home alone. Ever. For any reason. A really good friend of mine lives in Lincoln Square and when we are there the 2 kids walk over to the Park District park 5 blocks away all the time and play on the playground by themselves. Her son started walking home from school (next to the park) when he was 8. Both kids have cell phones and it really really safe there.
This may help:
Illinois law defines a neglected minor, in part, as "any minor under the age of 14 years whose parent or other person responsible for the minor's welfare leaves the minor without supervision for an unreasonable period of time without regard for the mental or physical health, safety or welfare of that minor."
There are 15 items that determine interpretation of the sentence above. You can find them at http://www.ilga.gov/legislation/publicacts/pubact90/acts/..., but here they are:
Whether the minor was left without regard for the mental or physical health, safety, or welfare of that minor or the period of time was unreasonable shall be determined by considering the following factors, including but not limited to:
(1) the age of the minor;
(2) the number of minors left at the location;
(3) special needs of the minor, including whether the minor is physically or mentally handicapped, or otherwise in need of ongoing prescribed medical treatment such as periodic doses of insulin or other medications;
(4) the duration of time in which the minor was left without supervision;
(5) the condition and location of the place where the minor was left without supervision;
(6) the time of day or night when the minor was left without supervision;
(7) the weather conditions, including whether the minor was left in a location with adequate protection from the natural elements such as adequate heat or light;
(8) the location of the parent or guardian at the time the minor was left without supervision, the physical distance the minor was from the parent or guardian at the time the minor was without supervision;
(9) whether the minor's movement was restricted, or the minor was otherwise locked within a room or other structure;
(10) whether the minor was given a phone number of a person or location to call in the event of an emergency and whether the minor was capable of making an emergency call;
(11) whether there was food and other provision left for the minor;
(12) whether any of the conduct is attributable to economic hardship or illness and the parent, guardian or other person having physical custody or control of the child made a good faith effort to provide for the health and safety of the minor;
(13) the age and physical and mental capabilities of the person or persons who provided supervision for the minor;
(14) whether the minor was left under the supervision of another person;
(15) any other factor that would endanger the health and safety of that particular minor.
So, based on the above checklist - I would interpret:
One child with no disabilities and who doesn't need life-sustaining medicine who would be able to get in touch with you at work if needed, has access to nutritional food and medical supplies (if she cuts her hand or whatever), in a (relatively) clean house and is old enough to articulate what she would do in an emergency would be fine under IL law.
As far as your gut tells you - go with what you feel is best. Only you know your neighborhood and your daughter. If you're not ready, you have the magical age of 14 to back you up on holding on a little while longer. You can always try it and see how she does.
Good Luck!