I always find her the easiest,, as she's the most willing to kamikaze into my squad.
If she's immune to overwatch, I bring bladestorm rangers, and heavies, along with one of the class she's weak too. Last night on the Switch she ran through my squad of 4 rangers and an auto attack Mox (schimisher weakness) and was cut down before her turn ended. Alien hunter axes help alot.. i did a mission to counter her "bending reed" ability during the gorilla ops.
If shes weak to overwatch, just set up an ambush with the crew that has the best accuracy.. Because she Kamikazes the squad, let her come to you, dont hunt her it will benefit her stringing your squad and overwatches out. That alien hunter bolt caster can mess her up, and you get an interesting quip anytime you use an alien hunter weapon on a Chosen.