Per Wikipedia -
Federal pardons in the United States are granted only by the U.S. president, pursuant to authority under the U.S. Constitution to grant "reprieves and pardons for offenses against the United States"
As the one in charge of the executive branch of the US government, only the president can authorize a pardon. Not their spouse. Not their staff. When the president won't issue a pardon, or cant, it is forbidden for another to do so.
