I love the feminist/lesbian metaphor that is Tara. Her redneck family tells all the women in it that they’re demons who will actualize their demon presences when they turn 20. What a wonderfully evil way to keep female power (in this case, literally magical power) in check! And Tara is completely terrified by the story to the extent that she lets it stop her from performing magic to her full ability, and lets it stop her from opening herself completely to her friends, even though her friends happen to be super-powered demon experts.
It takes Anya and Spike to uncover the secret and prove that it’s a lie. Anya’s brilliant and frank questioning of Tara’s dad (“What kind of demon?”) exposes the lie. Spike proves it by punching Tara to see if it hurts him.
So what we find out, in the end, is that Tara is an amazingly powerful woman who just needs people to love her for who she is. And the love she gets, not just from Willow, but from Buffy and her friends, will let Tara grow into what she needs to be.
We all need friends like that when we’re in college, or at that age. Friends who accept who we are and let us grow beyond our families, who might be actively holding us back, like Tara’s, but who more likely are just keeping us within the limits of their own experience. College is the time when we extend past our family bounds and grow into the people we choose to be. For women, it can be a tremendously powerful time or a really damaging one.