I believe that presently (June 2025), changes to contacts such as deletion of a contact will only be logged for the student where the action was executed at with no log of the action executed in the student's sibling audit. (the audit log accessible from header bar)
My school was recently investigating an incident where a contact was missing from student record as a result of the contact being deleted from the sibling's record and a deleted contact by who record in the sibling's audit would have been helpful.
