Smallville, Season 10

Jor-El:
There are two paths laid before you, Kara. You can leave Earth now and allow Kal-El to embrace his destiny, or you can stay and help him, risking the future of this planet.

Kara Kent:
Kal-El and I have fought Darkseid before.

Jor-El:
You involved Kal-El against my wishes. He was too weak then, and he was almost overcome by darkness. You have grown strong. Your will is no longer at the mercy of my command. You will need that strength to forge your own path. It is in your hands to choose.

Kara Kent:
You want me to just walk away?

Jor-El:
Kara, your own destiny is written. It is in another place and time. But this is Kal-El's battle, and he must fight it alone. Even though a time will come when he turns away from me, in the end, he will make the right decision. He is ready. This is his time.

Kara Kent:
He's the only family I have left. I have to at least warn him.

Jor-El:
Sometimes the greatest sacrifice a person can make is to give up what they hold most dear.