Played the role of "Catherine" in a San Diego production of David Auburn's play "Proof". Catherine is an unlikely mathematical genius who writes a groundbreaking proof at a very young age; McKellar is also an unlikely mathematical genius (she was the only undergraduate invited to speak at Rutgers University's biannual Statistical Mechanics) who wrote a proof at a very young age.
Had a 1998 paper published in Britain's "Journal of Physics A: Mathematics & General" with UCLA professor Lincoln Chayes and student Brandy Winn that provided a mathematical proof for a theorem dealing with magnetism in two dimensions. Her Erdos number is, at most, four; her Bacon number, by comparison, is two.