Even though the thing that got her on board was Eron's letter. She just somehow thought Eron's letter was a righteous callout of unethical activities.

Even if he wasn't a fucking liar, Eron demanded a staggeringly disproportionate response in return for his wounded dudebro status. Chuds are terrified of infidelity (not their own, against their partners) and it gets violently, even murderously, out of proportion.