Is it permissible to benefit from books in a high school library not designated for me, when my sister, who is a teacher, borrows them for my sake?

"The matter of borrowing books from the school library depends on the school's regulations. If borrowing books for teachers and taking them out of the library is permitted, then there is no harm in the sister borrowing them for you so you can benefit from them, provided she seeks their permission for you to read them. However, if they do not permit it, or if the regulations do not allow it, then you are not entitled to benefit from them without permission; because benefiting from books by reading them is not permissible without the owner's permission."