Gas stations these days have special disconnects for people like this so if she were to bring the nozzel back, they might not be out much money. While I've never seen anyone drive around with a gas station nozzle still in their car in person, there are many dash cam videos of it online, leading me to think that it's not as un-common as it should be.

There is also plenty of security camera videos of cars trying to drive away from gas stations with the nozzle still in their tank and no disconnect, and often it ends in a gas pump tipping over, fuel flooding out, and an explosion.