"Are you THAT short on ARs or need cheap equipment that badly?"

You get much better ARs from story events, and there's only so much that you actually need. If you need a cheap AR and already have FNC though I guess she can be useful.

Her exclusive, while it does give her more strength, doesn't let her outperform many 4* ARs.

The Night Empress. Unfortunately, she's been going the way of many a monarch with the lower class overthrowing her. She used to be the last word for night battle ARs, but with AS VAL's mod, she has fallen behind. Turns out, being able to use a crit scope at night is very good. That being said, +200% damage at night is still decent and if you can't afford the mod, she's a good replacement.

Also, while enemy armor stacks superhard now, it's actually fine if you have sufficient +FP on your ARs to punch through. If you don't though, this still wont save you.

Another grenadier that's not useless. Her grenade fires after just 4 seconds, making it actually matter, and either makes hit enemies take 115% damage for 3 seconds (3 or more hits) or buff her own damage by 60% for 8 seconds.

The self buff isn't too useful, giving her damage output on the lower end of usable at least, but since she hits a wide area she'll probably trigger the much more useful debuff. While much better dolls have largely obviated the need for this, maybe it'll be useful for someone. I dunno.

She does well at corpsedragging in some night maps but I don't know if anyone even does those anymore, doubly so since the main benefits {extreme low cost and mats for upgrading equipment} are no longer as relevant as they once were.