Okay, this actually makes sense. Rumple didn't teach Cora and Regina magic. He taught them how to tap into and use the magic they were born with. And it really plays in to the whole magic gene thing. Since Cora was born with magic and passed it down to her daughters. And Zelena passed it down to Robin. Anastasia and Drizella were born with magic, but neither of their parents have magic. It's possible that the girl's grandparents had magic.
And I don't think being a product of true love factors into having magic. Hear me out. Emma has magic, but not because she's a product of true love. It's because she's a Savior. Aladdin, another Savior, has magic and isn't a product of true love. Same goes for Rumple. Though his Savior magic was taken from him when he was a baby. Aurora is a product of true love, is not a Savior, and has no magic. Emma, Aladdin, and Rumple were born with magic because they were born to be a Savior. Rumple lost his magic when Fiona used the shears to cut his ties to his Savior destiny. Aladdin also lost his magic when he cut his own thread.
Though Rumple was born with magic, he lost it because of the sheers. So Baelfire wasn't born with magic. Of course he became magical again when he became the Dark One. And Gideon was born with magic. Not because he was a product of true love (which we was), but because he inherited it from his Dark One daddy.





















