You sure didn't mention it in the initial post. If she was handy with a wrench, and she planned to change her own oil, that sure would have been a pertinent detail to include in the post. Just as including the engine type. Since, it seems that several pertinent details were left out, maybe you got some replies not to your liking.And why are you assuming that?
For a gently used Corolla (and I am assuming that since it hasn't been mentioned that the car is driven hard) , any synthetic oil of a grade that the owner's manual suggests would be more than enough. Salt and rust is more likely to get the car, than any oil choice that the owner makes.