Travel insurance won't do anything if she just decided she wanted to drive instead.

You can cancel the ticket. You'll get the full value of the ticket back - can be used for one year from the date of issue - but you'll have to pay whatever the change fee is when rebooking. Since she is driving - ill assume the ticket is domestic, so the fee is likely $150. Thats assuming the fare isn't something that can't be changed - which happens with some usually unpublished fare - like Priceline name your own price et al.

Funds can only be used by her, but if the new ticket value is less than the old, the balance after rebooking will come in an electronic voucher which can be used by anyone.

Only hope of getting actual dollars back is hoping for irrops, etc. and flight gets canceled or severely delayed.