Mum Shoots and Kills Daughter After Mistaking Her for Boyfriend

Read this and tell me if it was insanity in play or just lack of anger management skills.
A Florida woman was arrested and charged with killing her daughter after mistaking the 25-year-old woman for her boyfriend.
Adele Bing, 52, was charged with second degree murder in the death of Rudy Bing, who was shot at her mother's front door, WFTV.com reports. Adele Bing was also charged with child endangerment. Rudy Bing was holding her 4-month- old baby when she was shot after she knocked on her mother's door. The baby was not injured.
From WFTV.com: Police said Adele Bing, 52, had an argument with her boyfriend, James Lane, earlier in the day and allegedly hit him with a gun. Lane went to the hospital to be treated for his injuries when officers said they received a call about a shooting at Adele Bing's home. Authorities said Ruby Bing went to visit her mother and knocked at her front door while holding her 4- month-old baby. Police said Adele Bing was still upset about the argument she had with Lane and thought he was the person knocking.
Investigators said Adele Bing armed herself with a baseball bat and a handgun, and as she opened the door, she fired a shot, hitting her daughter in the upper chest. The 4-month-old was not injured, but Ruby Bing died at the scene.

I still don't know..