Rey is Anakin's twin sister.

She's been frozen in carbinite for over 60 years.

Anyone who could have taken her away would also have taken him.

"No. There is another."

It's doubtful that Yoda is talking about Leia here, because Leia doesn't seem force-sensitive.

It could very well be Rey, tucked away and carbon-frozen on some Sith world. Probably taken away by Anakin's father, just in case Ani wasn't the chosen one.

"No. There is another."

It's doubtful that Yoda is talking about Leia here, because Leia doesn't seem force-sensitive.

Yeah, that whole "my father has it, I have it, my sister has it".

Straight from RotJ

Leia: Luke, don't talk that way! You have a power I don't understand and could never have. Luke: You're wrong, Leia. You have that power too. In time you'll learn to use it as I have. The Force is strong in my family. My father has it. I have it and... [looks directly at Leia] My sister has it. [waits for the words to sink in]Yes. It's you, Leia.