Linebacker women are at
least 3 sigma from "normal"/average.
As I said, her testosterone may be very high for a woman or it has been supplemented in some way.
She is on the right tail of that curve at least at 3 and probably substantially past it. The linebacker women you know also fall in that category and it is likely been bred for in your area. You live in a frontier like area don't you? A few generations of the women who settle down and stay being the ones of brawn and the curve shifts right.