2000 Ford Taurus Transmission - ? - Seems odd?

My cousin has a 2000 ford. She just had the transmission rebuilt last year, warranty just ran out of course!

The car has 114k less than 10k since rebuilt, fluid looked fine.

When I drove it everything is fine for a few miles, then the car acts like it is in neutral. The car will not engage in reverse or drive. I was stuck 3 mile away from her house. Turned the ignition off and started the car again. It drove fine for two mile same problem. Turned the car off and back on then made it a mile, same thing. Off - on then back at her house. Could this be transmission control module, torque converter, or does it need rebuilt again? What else can I do to try and diagnose this problem?

Could this be something that the shop missed the first time, meaning that the tranny was rebuilt correctly but the torque converter did not have enough fluid?

No engine light?

The pan needs to be dropped. I would first check for trash in the pan then check the filter. Make sure it is seated properly and not stopped up with trash. Did you call the trans shop to see if they would do anything for you?? With less than 10k and just over a year since the rebuild, they should at least check it for you. If they refuse, then I would have another trans shop evaluate it to see whether the other shop did wrong. Let us know what you find out.