Why was mallam sile's wife (abeeba) called the "man checker"?

The reason is that Abeeba took the initiative with the man who owed Sile money. He refused to pay it and she got into a physical altercation with him. She beat him up, as she was a rather large and fierce woman. Her husband, on the other hand, was meek and had been bullied and manipulated much of his life. She took a protective stance.