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Details of the service are being confirmed, and Mr McKay said they would be well publicised so people had plenty of time to make arrangements to attend.
A condolence book opened at the Ashburton District Council on Tuesday will also be available at the service.
Three memorial Facebook pages have been set up, with hundreds of people going online to post their memories of Peggy Noble and Leigh Cleveland and their support and well wishes for Lindy Curtis, who remains in Christchurch Hospital.
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The daughter of Mrs Noble's best friend posted a touching message on one page.
"She won my heart the first time I met her," wrote Andrea Creighton.
"She became my mum's best friend and they played outdoor bowls together, winning enough championships to sink a ship.
"Peg was a woman I really looked up to. She was a shining star... I feel like I've lost a family member too - she was just that kind of person who easily became loveable."
Ms Curtis' teenage daughter also took to Facebook and thanked friends and family for their support.
She said "everything's fine" when asked how her mother was doing.
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