like My Mod said. syphon the old gas out and put it in the old ladies car. I would refill with fresh premium. If you can get your hands on some race fuel mix it with premium to get your octane up to mix with any fuel that you didn't syphon out. The race fuel thing is over kill but what the heck it smells good.
Race fuel not needed, especially at today's prices. Fresh premium and you will be good to go.