S.C.
My husband works downtown, so we go there a few times a year for lunch. My kids love to eat lunch at the Avenue of the Americas. We watch people ice skate. get their shoes shined and go up the glass elevators. They love to play near the fountains around Nasher. They love to listen to the bells at the Cathedral. Your daughter really might just enjoy the people watching. It's good fun and free.
The Museum of Art does have a kiddie area where they can explore things. But that will cost money.