I'm going to be the contrarian here and say I would go with a lesser oil and change it twice as often, if she's short tripping the car that often in a colder environment. Amsoil is a great product, no debate there, but having gas in the oil is bad whether its Amsoil, HPL, Redline, or run of the mill Supertech. A few blasts down the highway isnt going to remove it either. Running 5 miles at a time twice a day in a cooler part of the country is going to have this poor car in open loop most of its life, and thats not good.
A Corolla will run forever on just about anything you can buy at Walmart for $26 a jug.
It does not need a once a year Amsoil change. It needs a twice a year change with run of the mill Supertech, Mobil 1, or Quaker State. And the cost to do so wont be much different. And tell her to stick $1 a week into a jar. After a year, there's another paid-for oil change.
Sometimes the best oil isnt necessarily the better choice.