Mrs Murray, who coached the former British number one as a teenager in Scotland and was a mentor to her, said: "I don't have the words to say what an incredible person Bally was."
Baltacha was diagnosed with the illness in January, just two months after retiring from tennis and only weeks after she married her long-time coach Nino Severino.
She and Judy Murray remained close and worked together in recent years through Mrs Murray's role as captain of Great Britain's Fed Cup team.
The pair memorably cried together at Wimbledon in 2012 when Baltacha was awarded an Olympic wildcard.
Mrs Murray was also a patron of Baltacha's academy in Ipswich.
Mrs Murray added: "How loved she was, and what an inspiration she will continue to be to everyone who met her.
"This is an awful loss for tennis for all of us who knew her and loved her but most of all for Nino and her family.
"My thoughts of course are with them. She was one in a million, an absolute gem."
Mrs Murray shared Baltacha's passion for inspiring children to play tennis and fulfilled her commitment yesterday to give a masterclass to a group of junior players.
On Monday, Andy Murray was among a number of players to stand on court and pay tribute to Baltacha with a minute's silence at the Mutua Madrid Open.
On giant scoreboards, a picture of Baltacha beaming her customary smile flickered across the screen with the inscription: "We will miss you."
The Dunblane star, accompanied by his brother Jamie, looked sombre and was clearly moved by the tribute as 40 players and officials paid their respects.
He and his brother had known Baltacha since childhood.
Within minutes of the tribute, their mother tweeted a picture of her sons standing in line to pay their respects to her close friend.
She also posted a picture of Baltacha's charity appeal #rallyforBally with the message: "We'll Miss you Bally, Rest In Peace."
Born in Ukraine but raised in Scotland, Baltacha competed under the British flag on the WTA Tour and in the Fed Cup, where she was part of the national team for 11 years.
She came to Britain at the age of five when her footballer father Sergei joined Ipswich prior to heading north to play in Scotland, and forged a tennis career despite battling a liver condition since she was 19.