http://www.pcmag.com/article2/0,2817,2497959,00.asp
Maybe in software mode, remember that OpenGL mode (especially gzDoom 2.0) can be quite demanding for integrated graphics chipsets.The situation has improved over time (my E6430 with HD Graphics 4000 can run gzdoom 1.x nicely), but at one point, OpenGL mode with integrated graphics had bizarre problems like this:Sorry but you are not allowed to view spoiler contents.
Have you tried QZDoom? It's the successor to ZDoom, the only two feature that were GZDoom only that TUCQ used (truecolor textures and dynamic lights) are both implemented in it, so the game should run fine as long as her computer can run it.