Wendy Dodd, 41, of Headingley, Leeds, had been drinking and had smoked cannabis when Charlea Fox and Jasmine Neville drowned in the River Wharfe near Arthington, West Yorkshire, Sheffield Crown Court was told.
The judge, Mr Justice Poole, imposed a jail sentence totalling 15 months but suspended it for two years because of the defendant's severe mental problems. He described her behaviour as "feckless and irresponsible" but said the other adults in the group had been wrong to leave her in charge of the children.
He added that Dodd had suffered severe post traumatic stress as a result of the tragedy and feared she would take her own life if she was sent to prison.
Dodd had admitted two charges of cruelty by wilfully neglecting each child in a manner likely to cause unnecessary suffering or injury at an earlier hearing.
At the earlier hearing - at which Dodd was formally acquitted on two charges of manslaughter - James Stewart QC, prosecuting, said the two girls, with Charlea's parents, Dodd and other adults had travelled 12 miles from their homes in Leeds for a party to celebrate Charlea's eighth birthday in July 1997. Dodd was left in charge of the youngsters while the other adults in the group went to get supplies of drugs.
Mr Stewart said Charlea could barely swim and Jasmine could not swim at all. The girls had gone paddling and one was heard to say: "Let's play Baywatch - you rescue me."
Neither Jasmine's parents or Charlea's parents attended the sentencing.Reuse content