CNN tour is awesome, so is the aquarium. If she’s a college football fan, the College Football Hall of fame is actually pretty interesting (and I’m not a big fan like the folks I went there with!). These are all walking distance I believe.
World of Coke is good too. FYI the way the aquarium is set up, you can choose which exhibits to see first if she has limited time. Of course, you still pay full fare 
Sorry the weather is so crummy! We haven’t had a full week of rain like this in a very long time.