Who is Ekwefi? What incident involving Ekwefi and Okonkwo occurs? What does this incident demonstrate about Okonkwo?

The second day of the new year is the day for wrestling. Ekwefi, Okonkwo's second wife, loves the wrestling matches. It was watching Okonkwo defeat the Cat that she fell in love with him. She married another man, but a few years after that she ran away from him and came to live with Okonkwo.