What has happened to the grass?

When you say 'gone', do you mean that the grass has died? Could you please give some more information? Is the grass going brown/yellow?

I have several more thoughts going around my brain - was the lawn turfed or sown? If turfed, was the soil properly prepared?

Does she live near a farm where there has been crop-spraying?

I am sorry to bombard you with questions, Montana, but to help give a sensible and helpful answer, we really need to know more.

Have any other plants (other than the grass) died? Is the ground very hard or very water logged? Has your daughter used any type of fertilizer or herbicide?

I have had this problem as well. I have a very tiny back garden with an even smaller area of lawn and grassy path. All the grass has died apart from a few small strands.
The ground is not waterlogged, and the soil should be in reasonable condition ( was re-turfed on new compost last spring). I do not use any pesticides at all in the garden. I have recently spoken to a turf supplier who presented an answer. Nearly a third of the back garden is made up of a pond, and during the summer months I let the grass grow maybe to about 10cm or so, only trimming the top so that the froglets could hide. In autumn when froggies were gone I cut all the grassy areas back to probably 1 cm or less high to neaten the whole area up.

I have since spoken to a turf supplier who said that if you cut more than 1/3 to 1/2 of the grass leaf the grass will die.
I cut a lot more than half of the height of the grass and now have an explanation for my dead lawn.
I don't know if this answer is relevant to your situation, - your lawn demise may be due to other causes than this.