According to Ontario, Canada's Windsor Star newspaper, Kerri Yascheshyn, 17, had been receiving daily phone calls from the star since late January, after the initial contact between the two had been arranged by the Children's Wish Foundation.
But it was Madonna herself who instigated and continued the growing friendship, says the paper, and she and Yascheshyn, an aspiring actress-dancer, shared conversations on such subjects as dancing and the afterlife.
Madonna also sent books to Yascheshyn -- who was suffering from a virulent but rare form of liver cancer -- as well as case of what Madonna called "healing water."
Madonna's own mother, a French Canadian, died of cancer in 1963, when her daughter was five.
"Madonna was very positive and encouraged Kerri to pray," said Kerri's mother, Gail Yascheshyn. "She kept telling her not to be negative, and would call whenever she thought about Kerri, sometimes from her cell phone."
Kerri died last Sunday, and her family, in a statement, said that Madonna's calls meant a great deal to the teen.
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