I get the details of different distributions mixed up but it is possible that the PCLOS live cd + installer has a repair option. I didn't want to leave you hanging but I'm too tired to try it out now and I'm busy all day tomorrow so I figured I could at least suggest that you boot the live cd, run the installer, and see if it has the option to repair an installed system.
I use PCLOS every day so I know that it is stable but it is possible to cause problems if you are learning something and make a mistake. The thing that makes Linux so cool to learn on is that installing is easy. You can always just reformat the partition and reinstall the operating system. I'm not saying that anyone changed anything. I'm just saying that it should be okay to allow your daughter or yourself to experiment to see what happens and reinstall if things go badly.