In answer to the original question, I think that yes, the instructor is correct. Broadly speaking, she would be best off with the longest weapon that she could practically carry, regardless of whether she's a man or woman. Of course, the operative word here is practical. I believe short swords were used not because they were amazing weapons, but because they were easy to carry without dragging on the ground.
Here's a guy who knows a lot more than me who addresses the subject directly:
Thank you Vaporo very much for sharing that.