Why not question it?
The President has secrets, etc. I can see protecting him with an agent. Once he passes, why does the wife need protection at tax payer expense. The Clintons have millions. If Bill passes away, why would Hillary need secret service?
(Below is probably for Jackie O)
In 1968, as a result of presidential candidate Robert F. Kennedy’s assassination, Congress authorized protection of major presidential and vice presidential candidates and nominees (Pub.L. 90-331). In 1965 and 1968, Congress also authorized lifetime protection of the spouses of deceased presidents unless they remarry and of the children of former presidents until age 16.[3]
Congress passed legislation in 1994 stating that presidents who enter office after January 1, 1997 receive Secret Service protection for 10 years after leaving office. Presidents who entered office prior to January 1, 1997 will continue to receive lifetime protection (Treasury Department Appropriations Act, 1995: Pub.L. 103-329).
Her husband may have disclosed classified information to her. This makes her a bit of an espionage target.
The First Lady is also a symbolic terrorist target.
Do you need to be reminded the world is full of crazies?