score:2
Yes, according to Timatic she is eligible for 24 hour TWOV.
However I would not recommend leaving the airport if you only have 4-5hr connection. First, going through immigration, getting a permit, and getting through the customs will take time; let's say 30 minutes. Walking to Maglev station, buying tickets and waiting for the train - another 30 minutes since the station is between terminals and is a bit of walk (assuming your mother can't run). Now Maglev doesn't bring you into the city center - rather into the subway station at outskirts. From there its around 20 minutes by subway to Bund. This adds up to 90 minutes, assuming everything went perfect.
Then if you properly time the subway and Maglev ride (and buy return Maglev in advance), you'll be back at the airport in around 45 minutes. Add another 45 minutes to clear security and passport control and for walking through. So you're looking at 180 minutes - 3 hours - from airport gate to center to airport gate - and you need to be at departure gate at least 30 minutes before the flight.
So you'd have only 30 minutes of free time (in case of 4hr layover). I'd say you can only do it if you been there before, know where to go, have all schedules in your phone, buy all tickets (maglev roundtrip and subway) in advance - there may be long lines to subway ticket machines, and know where to go. Otherwise I wouldn't do this, especially with your mother.