I'm not quite sure what you are asking. Are you worried about harming the mac os by booting a linux live cd? or are you wondering if she can tel the difference between mac and linux?
nope booting the live cd will not change anything from what is currently installed.
Edit: I would check the compatibility of the version of linux that you are using and the mac that you have. I have heard of a few issues with some of the linux distros and mac hardware.