GREENSBORO — The mystery of why a Greensboro woman killed two of her sons and three other children in her care before taking her own life has deepened after the discovery of two checks worth $10,600 written to her surviving 21-year-old daughter just before the woman went on a shooting spree.

The checks were made public in court records recently released as Mary Ann Holder’s $13,310 estate was settled in Guilford County Superior Court, the News & Record of Greensboro reports.

In November 2011, Holder shot and killed her 17-year-old and 14-year-old sons; her 17-year-old nephew and 8-year-old niece she took into her home after her sister died; and the 15-year-old girlfriend of one of her sons, authorities said.

On the day before the killings, Holder also wrote a $10,000 check to the wife of her former boyfriend that investigators think was an apparent settlement aimed at staving off a lawsuit prepared by her boyfriend’s wife, accusing Holder of stealing the affections of her husband.

Holder didn’t have the money to cover all of the checks, and no one can figure out why she wrote the ones to her daughter, dated two days before the killings.