This side quest, "Hush, My Darling," in Kingdom Come: Deliverance 2, begins not in Kuttenberg City, but in the nearby village of Miskowitz, located to the west. Prepare your blacksmithing skills; you'll need them!
Completing "Hush, My Darling" in Kingdom Come: Deliverance 2
Speak with Martha
Find Martha in the house adjacent to the forge in the southeastern part of Miskowitz. Ask if she needs help; she'll reveal her need for a blacksmith's assistance. Claim the quest by responding, "I'm a blacksmith! I'd be glad to help." If you haven't already, you can speak with the bailiff (standing near Martha) about Matthew, a member of the Dry Devil's group, to get additional context.
Craft Horseshoes

You may already possess the necessary materials. Two Farmer's Horseshoes will suffice. If not, gather two pieces of Scrap Metal and craft them at the forge. Return the finished horseshoes to Martha.
Find Victoria

Martha requests you deliver the horseshoes to Victoria, whose house lies south of the forge. Upon entering, you'll discover blood instead of Victoria. Examine the blood when prompted. Inform Martha of your finding; she'll suggest searching Sigismund's camp.
Sigismund’s Camp

Sigismund's camp is south of Opatowitz. (You might encounter Matthew on the path there). Question the blacksmith in the camp about Victoria; he'll mention a soldier named Black. Find Black in the infirmary tent—he's ill.

Black requires medicine before cooperating. Provide him with a Digestive Potion (craft one if needed). Allow a couple of hours for the potion to take effect. He'll reveal Victoria's likely location in the eastern woods.
Find Victoria at the quest marker. Converse with her; dialogue choices have no significant impact on later events. However, if you secured a promise from Black to care for Victoria, relaying this message offers her solace. This concludes "Hush, My Darling." Continue with main quests or explore other side quests, such as "In Vino Veritas."
Kingdom Come: Deliverance 2 is available now on PlayStation, Xbox, and PC.