A jury at Nottingham Crown Court yesterday decided after 15 hours' deliberation that both children were murdered by the new nurse on Ward 4 of Grantham District Hospital, Lincolnshire.
They also convicted Allitt, 24, of causing grievous bodily harm in attacking three other patients, Kayley Desmond, 15 months, Henry Chan, two years, and Christopher King, four weeks. She was acquitted of attempting to murder all three.
The jury last night spent its third night in a hotel; it will resume consideration today of charges against Allitt involving 10 other alleged victims, including two charges of murder.
Becky Phillips had been born prematurely. She was admitted to Ward 4 on 1 April 1991 with a stomach upset. Two days later Allitt called a colleague to see Becky, who she said had 'turned cold and clammy', a sign that the level of sugar in her blood was low. The incident may have been caused by an injection of insulin.
The next day, Allitt fed Becky: she also went into the baby's room during the afternoon. Within 12 hours, Becky had been taken home by her parents. They believed she had recovered; instead, she suffered convulsions through the night and into the early hours.
Shortly before she died at 3am, she awoke screaming and crying. Laboratory tests showed that her blood contained a massive volume of insulin, which the jury concluded had been given to her by Allitt.
Allitt murdered Claire Peck on 22 April. She had been left alone on the ward with the baby, who was there because of an asthma attack.
Claire suffered two assaults. When her blood was tested after the second a laboratory machine was unable to measure so much potassium.