My wife was driving back from her friends house.

The link doesn't work, but regardless, there are dozens of parts that can cause an engine to stall. If we could diagnose them over a computer we wouldn't need mechanics. If we COULD hold our hands on the computer and determine the part(s) that failed, would you have them and the tools to replace them?

GM fuel pumps are known for failing while you're driving. You'll still have spark. Crankshaft position sensors are common failure items on all car brands. You won't have spark and you might not have fuel pressure. GM owners are all too familiar with the poor generator design and the repeat problems, but if that failed there would have been plenty of warning signs long before the engine stalled. With no history or details to go on you do need a psychic, or a mechanic. My vote is for the fuel pump.