Big dmg bunny. Seems to me like building SMilk is fairly easy too since she only really wants 4x ele dmg and then maybe 2x ammo lines for comfort so you don't reload in-between full bursts, but rolling ATK lines doesn't seem that important on her since the buff would be so diluted by her 118%/220% self ATK buff.
I think crit rate, for her S2 distributed dmg, or ch spd, for the occasional full charge you have to do, could be good as well, but I really would only go for 4x ele dmg and 2x ammo.