Here is the plan:

1. mount / as read-only in fstab
2. mount /var/log, /var/run and /tmp as tmpfs
3. make an ext3 or ext4 partition for /home, as small as possible (the smaller the /home partition, the quicker the fsck)
4. tune2fs -o journal_data your /home partition
5. use the -a option in your e2fsck at boot
6. tell her to backup her data each week. No matter how she shuts her computer down, she needs to do that anyway. that is MANDATORY. Hard disk failure WILL happen. I don't know anybody that has never had a disk failure in his lifetime, especially when using a laptop with a 2.5' drive. Remember, the laptop lifetime is 5 years at best, and often less than 2 years. If it's a recent one, even less. And don't underestimate stupid moves. They happen more often than we think.