If you’re ever present or have remote access to her network, make sure sshd is enabled, and try to SSH into it to see what happens.
Q’s:
- Is this a laptop or desktop?
- If Desktop, what kind of cable is the monitor connected with?
- See if you can get
dmesgoutput (needs to happen during the event, but the machine is still accessible - hence ssh above) - Does the monitor have its own power saving settings?
The KVM is the most likely culprit. Remove it from the equation for awhile and see what happens.