She looks like a discount STAR-chan, although it's hard to describe anything that uses a stupidly expensive round like the 5.7 as a discount anything. She has a three second long cooldown and the skill lasts for two seconds. Her big thing is that she can also buff SMGs. She can be used either a mild firepower buff or an actually not awful evasion buff, the downside of which being that getting her evasion buff to work requires moving your dolls around.

....She has tank stats on a handgun with buff tiles that want her in the back. I'm not entirely sure why anyone thought this was a good idea.

I really want to say something good but the closest thing to a real merit that I can think of is "voiced by Ayako Kawasumi." She's basically a 3 star inferior version of P7 with an... "interesting" shape buff and less used than the cat nun. You are likely to be flooded with cat nuns in your eventual quest for Stetchkin. Also, sends you to jail.

Catgirl nuns should be met with fire. Honestly has some use but.. you are likely better off with someone else, due to her aura shape forcing you to push her to the side to give your tanks evade and kind of unflattering aura in general compared to other 4*s. Probably better as cores but she does have her uses. For example, combined with Welrod and Makarov, the +evade/-acc combo does funny things to enemy hitrates (though its impossible to reduce hitchance to zero). Niche, but you may find some use for such things.