Jaina wins
Malgus had difficulty with Leneer who is inferior to Jaina in every respect whether its lightsaber skill or force abilities. Jaina being more skilled than Kyle, Kyp Durron, Corran, Saba as of FOTJ, should scale well above Leneer and be capable of engaging him in sabers and winning in a terrific fight. His lightning won't be an issue for her, and he isn't capable of ragdolling her