Ok, never mind. I needed to have Trudy take it from a Werewolf too, but that's not listed as a requirement in the wiki here https://androgyny.miraheze.org/wiki/Questlines
Minor bug: Any time you "gain" a skill you already have, either it should just skip saying you gained it (like I've gained "Pet" over a dozen times), or in special cases it should say something else (like in this case, "Trudy teaches you X, but you already knew that!")
Suggestion: For the Trudy quest, maybe there should be a consolation prize, like more XP, or better, some sort of improvement in the skill, making it better than the skill you already learned. Like QuickCast could cost less mana, or Deep Focus could gain more.