I hardly ever crash with the Cool SL Viewer... Of course, I'm under Linux with a Nvidia card and its drivers (which are known to work best and stable with OpenGL applications)...
Perhaps she hits the crash bug introduced in v1.23.5.10 and fixed in today's release (v1.23.5.12).
No, but the video card brand and its driver can make a HUGE difference in stability (and sometimes, the latest driver is not the best)... Also, overclocking the video card or having it badly cooled down may lead to crashes since the viewer is quite demanding on the GPU... Nividia users should be aware that a recent driver by Nvidia actually broke the fan control and made some GPUs to overheat (for Linux this is fixed in the beta driver 195.36.15 and the former stable driver v190.53 is OK too).