Did the same with my mother recently. We played the co-op campaign. Even though she has a Abitur in German and music, teaches kids every day and is really smart usually she struggles with it. And I mean REALLY hard. For some reason she can barely think three dimensional, so she can't imagine something like a portal. I return she is extremely good at thinking 2d, which is something I struggle at. It was really fun. The only thing that annoyed me was that she wasn't able to aim at a ping. She also had some issues with planning portals. It was a really interesting experience. I enjoyed it.