Disclosure
Trophies in this game are glitched and may not unlock when you complete the task. You can try restarting the game and rebooting an older save, but you may have to run a new playthrough entirely.
When I ran through this I wasn't too sparing with my ammo. I protected myself the best I could and avoided enemies when I could.
I used four health kits and here are the points of where I used them as a reference for anyone reading the guide.
1. I used after the first boss. I got hit once
2. I used after the second boss -- I was lacking ammo and had to knife the boss. Try to conserve ammo to avoid using a kit if possible.
3/4 I used my last two before heading to the final boss for full health.
Zombies - are very easy to avoid and it shouldn't be hard to dodge them.
Knife legs - not really dangerous, can hit hard. It takes 4 pistol bullets to kill, so I recommend just dispatching them.
Hunter knock-offs - these guys are deadly, and you may want to try to have some saves ready for a backup. They usually end up attacking you from a bad angle where you can't see them at first and are very quick. I defeated them with 2 pistol shots then 2 quick shotgun blasts. If you can locate where they are you can fill them full of lead right before they get a chance to hit you.
*You can also cheese going in and out of doors. Shoot repeat, but if enemies get too close to the door you may screw yourself instead.*
Gardener - Just keep moving, he hits hard, but not too bad to dodge.
Maid - Very easy to fight if you have ammo. Just make sure you stun her on the furnace.
Stepmother - Magnum shots make quick work of her. Switch to the knife or other weapons to defeat zombies if she spawns them, then finish her with the rest of your magnum bullets