Sodly,
Long time chicago resident here: Help us narrow down the field somewhat... Got a few questions that might give us some good ideas...
1) Budget for the evening? (Don't be shy
)
2) Do you prefer more mainstream stuff or local/off the beaten path?
3) Are you downtown? WHat hotel?
4) Any particular dining preference? (Steaks, seafood, asian, CHicago Dogs, etc..)
5) Is she into shopping? What kind? (Bargain hunting, High-end, etc..)
6) Do you mind taking cabs, or shuold they be walking distance?
7) As far as museums, Historical, Art, Science, Aquarium, preferences?
8) Shows: Blue Man Group or Ballet?
So many many things to do, this may help fine tune...