Hooked Queen is Canon-- taking place in S6 when Emma and Regina go into Wish Realm. When Emma and Regina head home to Storybrooke from Wish Realm, they aren't alone going through the wardrobe. A brunette, beautiful 16 year old girl follows behind them to Storybrooke, strangely resembling Killian and Regina. The girl was born in Wish Realm to different versions of Killian and Regina. The child followed Regina for a sad reason that occurred in Wish Realm.

What if...... Once upon a time, The evil queen cast a curse upon an entire Kingdom, along with her very own sister. Once Upon a Time, Henry wasn't the only child of Emma Swan, The Savior. Once Upon a Time, Regina little sister wasn't just her little sister. I'm not good with descriptions.