Judy Murray has paid tribute to Elena Baltacha, who died of liver cancer at the age of 30 on Sunday.
Murray coached Baltacha as a junior in Scotland and then worked with her as captain of Britain's Fed Cup team.
She added it was "an awful loss" for tennis, those who knew and loved her, but most of all for her husband Nino Severino and her family.
She was one in a million," said Murray. "An absolute gem."
Murray added: "I don't have the words to say what an incredible person Bally was, how loved she was or what an inspiration she will continue to be to everyone who met her."
Baltacha, who was British number one for nearly three years and retired in November 2013, learned she had liver cancer in January 2014 - two months after retiring and only a few weeks after marrying her former coach Severino.
A host of tennis stars, including Martina Navratilova, Laura Robson, Andy Murray, Ross Hutchins, Tim Henman, Greg Rusedski, Jamie Murray, Jonny Marray, Anne Keothavong and Heather Watson, have agreed to take part in The Rally Against Cancer - Rally For Bally, a fundraising event to be held in Baltacha's memory on 15 June.
The mixed doubles exhibition matches at the Aegon Championships at Queen's Club, the Aegon Classic in Birmingham and the Aegon International in Eastbourne will raise money for the Royal Marsden national cancer charity and the Elena Baltacha Foundation.