notably, she wields a large bastard sword.
Recall in pathfinder, you could wield an oversized weapon that falls into a valid category, by taking -2 to hit, per step.
So, a bastard sword is a 1handed-ish weapon. Make it large and hold it in two hands. done.
And because of some goofiness with how damage scales with size, you end up with 1d10 -> 2d8, rather than the standard 2d6 of a greatsword.