This has no bearing on the Obama/Clinton issue. She has not been charged with criminality, and therefore cannot be pardoned for anything. However, when Donald Trump is invested with the office at inauguration, his appointed advocate can then place the charges.
However, at that point Obama no longer has any power to grant a pardon to anybody for anything except being offended by poor social manners.
Pardons may be issued to anyone for any crime, indicted, known, or unknown.
Some irrefutable FACTS: 1: The 'impeachment,' of a President of the United States, is a political process, not criminal.
I. Impeachment
..............A. Being formally accused of unlawful activity, committing a crime
..............B. Not necessarily being kicked out of office
II. Who can be Impeached? Article II, Section 4 of the Constitution
..............A. President, Vice-President, and all civil officers of the United States
..............B. Civil Officers include people appointed by the President (cabinet members and judges)
C. Members of Congress are NOT civil officers
..............1. Justice Department or an independent council investigates charges & presents them to the House Judiciary Committee
..............2. House Judiciary Committee (HJC) reviews evidence
..............3. HJC drafts Articles of Impeachment
..............4. HJC debates Articles of Impeachment (Nixon)
I would would argue that no specific charges were brought against Nixon, but they were in fact debating / deliberating just what to charge(s) {a.k.a. High Crimes & Misdemeanors } him {Nixon} with. Gerald Ford told Nixon, he didn't have the votes necessary to avoid an Impeachment. Hence Nixon resigned. {Democrats chance to avenge Alger Hiss} A young congressman from California named Richard M. Nixon was determined to expose Alger Hiss, a State Department official, as a communist.
..............5. Entire House of Representatives debates Articles of Impeachment & votes on them (Simple Majority)
..............a. If this happens, President is considered Impeached
..............6. Senate holds the Trial "Will the official be kicked out of office"
..............a. House Judiciary Committee acts as the prosecution-- presents evidence against the accused
..............b. Accused chooses own lawyers to present defense
..............c. Chief Justice of Supreme Court acts as Judge and rules on admissibility of evidence
..............d. Senate acts as the Jury
7. A 2/3 majority of the Senate must vote against accused to remove the person from office (Andrew Johnson, Clinton)