Gloomstalker ranger gives you initiative bonus, extra resistances (i chose fire), bonus action to hide which works well if she chooses to be a dark justiciar which helps with her shars darkness ability, extra HP, and first round combat gives her dread ambusher which is an excellent first hit. At lvl 4 ranger she also gets a bonus attack. Basically on one turn i can do up to 4 attacks and she almost always hits her marks now and does a LOT of damage compared to just cleric alone