More data is needed to identify the "problem areas" in child deaths, Dr Hilary told Daybreak this morning.
The Government will today announce a national pledge to cut child deaths, being amongst the worst in Europe for child mortality rates.
Dr Hilary said that we need to find out why we are missing the diagnosis of diabetes and asthma, and that the Government's proposals today could help to solve this.
More top news
The author said "It's been wonderful" as fans mark two decades since the children's books opened up a world of magic to millions.
There was something very striking about the pact, which implies the new agreement could remain in place even if the prime minister does not.
The royal will visit the site of the deadly attack at Manchester Arena as he remembers those killed and injured.