No United States president has ever been indicted or charged with a crime during or after their presidency. (According to my search / this Quora post)
Has a president's family member ever been indicted or charged during or after their presidency?
I know their family gets secret service protection, often (always?) after the president has left office. But I could not find any formal legal protections on them. Has it ever happened, or has the informal legal protection prevented it throughout US history?
Defining family member: Part of their nuclear family at the time of the indictment. The president could be dead when it happens, and would still be interested.
Edge cases that don't strictly fulfill the question (e.g arrest but not indictment, or non-nuclear but still close family member) are still interesting/noteworthy, but probably worth starting with this more narrow criteria.