Cowarna Patterson sobbed loudly after the verdict was read.
The jurors Thursday found the 18-year-old Rockford woman guilty of stabbing her neighbor to death because he was teasing her.
Tyrone Carthell died Aug. 17 when Patterson stabbed him once in the back with a black-handled kitchen knife. The blade pierced an aorta and the 15-year-old bled to death.
The two had been teasing each other while walking with a group of friends. But Patterson became upset when the boy made comments about her feet, hair and other physical attributes.
Before deliberations began Thursday Patterson took the stand. She said she didn't intend to kill the boy.
She said, "It just happened real fast."