Last Wish is a player (any enemy really) delete button if you're good at headshots (so a PC-biased weapon
).
Appropriateness and Mercy is gonna be pretty much your best DPS combo with that gun, it will make it reload and shoot super fast. With 5 stacks Mercy can be active 100% of the time.
Ultimately I can't recommend Stoicism enough as general use faction card for her, she becomes quite the tank if you get wounded. All of her weapons are very deadly so you can usually out-DPS whatever is trying to kill you, as long as it's not something that can use a finisher, or a large mob.
Harmony is always good to have a copy of, a staple for anyone using Sigh, works good with Vortex too. Retribution is probably gonna be your best raider support card for healing.