Hey uselessowl,
Got eyes on your One Pager and had some thoughts while reading:
1. This is just a personal note for me, the word Slay in red letters caused me to read this with the Buffy the Vampire theme in the back of my head. And I loved that show haha.
2. The character creation is short and sweet. I like that the adults have more HP and the kids are harder to hit. Very thematic. And great job with the sentence constructor. The only thing I'd add... have the players choose their family last name together!
3. Some suggestions on the combat. Put physical boxes where the players can place the dice on the sheet to denote a space for Difficulty of Monster, Number of Monsters, and How Close with their numbers below. It'll just be easier to track.
4. I think you meant to flip the to hit rules. 1-3 no / 4-6 yes. Based on the levels to hit, I'm pretty sure.
5. I wish there was more of the social element but just because I'm enjoying this. If you want to fit more in, you could even drop the front down / go for a multicolumn setup. I think you could add some really cool stuff.
6. Your last note in the GM section is very on point haha.
Overall, nice job! I really want to re-watch Buffy now haha.