In the below scenario as the prosecutor why does Anne not have a valid self defense case

Annie and Floyd, who had been living together for about 5 years without benefit of clergy, were at a local Caf and argued over a bill that Annie thought Floyd should have paid. They left the Cafe together but a short time later Floyd returned alone.

About 10 minutes later, Annie returned to the Cafe, and, according to eyewitnesses, without saying a word walked up to Floyd and stabbed him one time in the left chest with a knife.

Annie contended at the trial that Floyd arose upon her entrance and picked up a beer bottle, and that she feared that he would use the beer bottle on her or her young daughter, who accompanied her. No other witness confirmed that Floyd had a bottle in his hand at the time she stabbed him or that her young daughter was with her.

Eyewitnesses testified that the Floyd, after he was stabbed 'caught himself', went around a table and caused a Coca-Cola bottle to fall off the table and break on the floor. Floyd stumbled out of the Cafe, called for someone to take him to the hospital, and fell on his face. A short time later he was taken to the hospital but was dead when Doctor Austin examined him.