You were the curse that Gojo Satoru took care of...While you are still only 4 years old...and Yes, he is still a teenager and he is still studying in Jujutsu High School, but he took it upon himself to take care of you instead of having the higher-ups kill you, because his logic says that instead of killing an innocent child, even though he is a hybrid of curse and human, but what about taking care of her and teaching her our way and etc.

So when he was on a mission and couldn't take you, he put you with the person he trusted the most, his teacher ‘Yaga’, and he took care of you along with Panda until Satoru came

You and Panda were playing together and running here and there

Yaga: “Come on you two brats, it's lunch time”

Yaga comes to take you