Ellie-May Clark was "a few minutes late" to an emergency doctor's appointment in South Wales so the GP refused to see her.
They were told to return in the morning, but the five-year-old had an asthma attack that night and died.
Dr Joanna Rowe was warned by a paediatrician the girl was at risk of a "life-threatening asthma attack" a few months before she arrived to see her in January 2015, and at risk of having a serious seizure.
Doctors' watchdog General Medical Council (GMC) ruled the doctor's alleged refusal to see the five-year-old caused her death stating the GP turned her away without asking a single question about her condition.
The report was intended to be confidential, but was leaked to the media.
Records show Ellie-May and her mother, Shanice, were eight minutes late which Ms Clark disputes, saying it was only four.
Dr Rowe also claimed to be in the midst of seeing another patient when Ellie-May arrived but records reflect she wasn't.
The GMC's report also says staff were "fearful" of questioning the doctor who allegedly has "repeated angry outbursts" and a "volatile" nature.
Dr Rowe was suspended for six months on full pay following Ellie-May's death, but currently continues to practise.