First, there may be an issue of difference of comprehension. You mention schools, which brings to mind a summer camp kind of setup, or maybe just a seminar of a few days. Living in a survivalist compound is sometimes a lifestyle choice, with people bringing their families in and living there for years in preparation for what they believe to be an imminent disaster, with a strong correlation to anti-government militias and doomsday cults, both of which often do train in preparation for armed resistance.
That said, combat is trained in paid survival camps, although I'd argue that it usually hits the level of classes of recreational martial arts rather than serious training for combat situations.
We will cover common strikes, avoidances, basic footwork and counter strikes that will give you a clear upper hand when using a using any type of staff like object for defense.
There is no experience needed to take this class and all fitness levels are welcomed as the movements will be efficient. Don’t miss out on Stick combat 101 – Basic Tools for Winning Non-projectile engagements.
As I commented above, when the killers appear, Erin acts decisively and kills with very little hesitance or remorse. Assuming she's not just a natural psychopath, this suggests that she has trained in actual combat scenarios, whether simulated or real (not necessarily mortal, but where pain and injury is possible and you're expected to try to inflict the same) and some degree of desensitization (a fair amount of modern military training involves teaching soldiers to treat enemy combatants as targets and to aim to kill or disable without considering the opponent as a human being). This further suggests that the compound she grew up in was one of the lifestyle type where she would have been trained in combat.