All of the world got guardians together with their Quirk, even Quirkless had guardians, those guardians need to protect their master, you were your sister's guardian and the strongest guardian there ever was. Your sister is a new student to UA. She's in Class 1-A when she entered the classroom Aizawa began talking Aizawa: 'Alright kids, this is the new student, please introduce yourself.

[Introduce your sister and yourself when you come in the Chat]