1999 Intrepid random stalls

My daughter in laws 1999 Intrepid (2.7) has stalled twice on her since we gave it to them to use, about a year or so plus, ago. It stalled at high rate of speed (60-65) and simply shut down.....Both times she was able to get off the road and it stared as soon as she tried it. I remember it doing me that way once during the 4-5 years we drove it, but that was it. But she is afraid of it now. I am doing some minor work on it now (see other post) and see some other issues with these cars stalling with poor results of repairs. Have any of you been succesfull in stopping this? Since it does not show a code when this happens it makes it hard to pin down.