What exactly does she need it for as that will help decide what’s best.
I’m typing this on a Chromebook and it’s excellent at what it does, unlikely to suffer from viruses, basic OS so snappier in use, great battery life etc but might not be compatible with everything software wise she needs to use.
I recently bought a few laptops for work. If you need full windows then the HP STREAM 13 is pretty good. It’s like most chromebooks as it’s designed to be very portable and quick despite modest components as it only has flash storage of 32gb but no moving parts in the HDD.
Yes you could get a laptop with 500gb of storage for similar money but it’ll be better to encourage her to store stuff in the cloud (rather than on a HDD that’ll not get backed up and fail eventually losing everything!) so it can be accessed at School without emailing, memory sticks or other ways you might lose data in transit.