She probably has a humor that is different to yours.

My husband and I have a very good marriage, and one of the main things that keeps me in love with him is that he is the funniest guy on the planet, to me. I just love his idiotic comments about pretty much everything. - Without that, I dont think a marriage can survive the various ruts that long relationships occasionally fall into.

If your girlfriend and you dont have compatible humor AND you derive a part of your sense of worth from being able to make people laugh and being funny, you might be incompatible. But please dont tell yourself or others, that she just doesnt laugh at all, never, ever! Its much more realistic to say; She just doesnt share the same humor.

I want to say, I have never met a person who never laughed or smiled. Like never. Thats why its much more likely that she in fact, does laugh, just not around you or at your humor. Its more honest I think if you accept that you havent met the only person on the planet to never laugh, rather have a relationship with someone whom you are not compatible with in that area.