A teenaged girl is thrown into a heaping mess with the gathering forces of evil, an axe weilding ghost maniac, and the task of hiding her darkest secret as cursed witch.

Agreed with the others here as a goal is not really- clear.
But just going on what you wrote and how I would do it-

"A closeted teen-aged witch tries to keep her secret and save the world when a tide of ghastly evils threatens the planet."

As Richiev said, she doesn't have a goal, at least a positive one. "Task of of hiding her darkest secret" is negative, reactionary and passive. What is so interesting about watching a character hiding, suppressing her defining characteristic, the source of canny powers and abilities? You can't build a mini-series, let alone one episode, around a negative, or passive goal. The story should always be driven by a main character with a positive goal.

Maybe she's a witch and a cursed one. But the plot is a conspiracy against the main characters original intention; it must compel her to be proactive, to use her 'bewitching powers" for some positive objective goal.

You haven't given your lead character a goal. What does she want? Just curious.