Villainess: Reloaded! Blowing Away Bad Ends with Modern Weapons Volume 2

Nine-year-old Astrid has been reincarnated as an otome game villainess, and now she’s locked in a battle with fate that she refuses to lose. Although she has found herself powerless to stop the sequence of events that she knows will end with her destruction, that could all be about to change. With a talent for magic and some knowledge from her geeky past-life, she’s already made herself an automatic pistol, an automatic rifle, a shotgun, a machine gun, and a grenade launcher. That’s quite an arsenal for a little girl in a world where soldiers still use crossbows...but it’s still not enough! Astrid won’t stop until she has enough firepower to make her unassailable, and that means bigger guns, more combat experience, and some morally questionable magic. She’s going to tear fate a new one, even if it means bringing down an entire empire!

[From J-Novel Club]