Post #1: “I am also planning on graduating a year early, so next year I’ll be a senior.”
What I said in my last post was that it looked like you hadn’t read the OP’s initial post and your response above suggests that is the case and that you responded to the second post. The test taking requirements for 2017 graduates are different than those for 2018. Hence the correction. I do not mean to be rude here. I was mainly concerned that the OP might get stressed about standardized tests requirements that might not apply in his/her case.
It might be helpful to the OP if you could provide information about where your sister will be applying that requires the new SAT as opposed to the old one for the class of 2017. I checked the UC requirements because you had mentioned the state of California and this page suggests that current sophomores and juniors can still submit the old SAT (It actually says current freshmen, but the page looks like it requires updating).
http://admission.universityofcalifornia.edu/freshman/requirements/examination-requirement/