My question involves child support in the State of: California

I am the guardian of my younger sister. She is now 18 years old and decided to live with our older sister. I have a child support case against my parents. The case requires them to pay child support until her 19th birthday unless she is no longer in school.

My question is, do I have to report to anyone that she has moved, or can I just pass the support payments onto my older sister to take care of the younger one? She still is enrolled in school.