Level bug? / Min Equipment? "The Prisoner"

I am also unable to beat it with 88 health. You/your fiancee could try to bring your archer in attack range to the ogre and let the archer do the mainwork, or return with a little bit more health.
131 health with the right tactic is more than enough, as I still have 41 HP left in the end (in other words you’re just 3 HP short).

You get a wooden shield later in the dungeon for free, which gives you an additional 33 HP.
Look here: