The only time we even saw Maladi with her saber drawn, she was lightning-ing at the same time.
Even in a duel she uses force to supplement. It was against an impressive duelist, but it does leave us no clear picture as to how well Maladi'd do in a 'pure' duel.
So force and all out, Maladi. Saber only, the fact that her dueling style is so force oriented means without it, Brianna likely wins.