why's Alero shutting off while driving? waterpumps bad, but always ran til now on 2004 Oldsmobile Alero

waterpump went a year ago. I just keep adding coolant as necessary. 2 days ago my girlfriend called saying it just died while driving it. I used my Arkansas TowTruck (Tempo & TowStrap) & dragged it home.I cleaned the terminals and charged the battery. She started it (against my advise) and drove it 10 miles. did her thing for an hour and drove home. She put it back on the charger so I wouldn't know. She drove today 10 miles and it died while driving it. waited 10 min, jumped it, drove 5 miles & died again! Electrical? or Sensor when hot?

Fix charging system. Had some connection problems at the alt.
1 more answer
test charging system and load test battery.did it over heat on her?