I have a theory: She's actually the main villain, and likes trolling adventurers by seeing how far she can mentally push them.
This is why the monsters all act patient with Alvin and the elf's antics, because they first don't wanna get in her way, then realize Alvin is just so pathetic they've decided it's more worth their time to partake in Alvin's adventure. This lets them become friends.
Do I expect a budding romance? No. But I suspect Alvin might be saving the world by being so weak he's distracting the demon lord/eldrich horror/etcetera.