Who stole the Paris Masterpieces? The art heist/divorce connection!

Why does everyone assume that the thief of priceless pieces of art from Paris’ Musee Moderne is male? I think its a woman, who had accomplices who worked for the museum. She was trained to walk like a man to throw off investigators from her trail. And why would she do this? What is her motive? She’s pissed off. It has something to do with a divorce.