As a fellow "fire-crotch" I can say, I think the issue here isn't really the red pubes or not, it is shaving or not no matter the hair color. If your girlfriend wants you to shave some, you probably should think about doing that.
Personally - I love having red pubes but I do shave my balls, and trim the pubes a little bit. Ever gotten hair in your mouth during sex? That's why I trim some.