As long as the flights aren't seriously delayed, she should make it.
O'Hare is very easy to navigate. Most likely she'll land in G and takeoff from H/K. It's a hike but it doesn't take that long at a good clip.
If she's truly worried, she should standby for an earlier MSP -> ORD flight. Maybe even fork over the $25 for "confirmed standby" if it's available.