Fusilier Gentle, from the Pollok area of Glasgow, was 19 when an IED exploded under his Land Rover in Basra in June 2004.
Speaking after the report was published, Mrs Gentle said she was pleased with its findings.
“I didn’t think we were going to get that verdict today but I’m really pleased,” she said.
“I hope he (Blair) goes to his bed and thinks ‘What the hell have I done?’ because he will never be forgiven.
“He will be remembered not as a prime minister but as a person who sent them on an illegal war.
“I would love to see him in court.”
Asked what she would say to the former Labour leader, Mrs Gentle said: “Why did you kill my son, send my son to be killed? Because I hold him responsible for the murder of my son.”
Speaking about the report, she added: “What we’ve been hearing and what we’ve been reading has been really hard and I think that’s why there’s a lot of mothers and fathers that’s been in tears today.
“A lot of us have held it back for weeks and what’s been confirmed today has really gut-wrenched a lot of us.” In total, 19 Scottish servicemen died during the Iraq campaign following the invasion.
The mother of Lance Corporal Allan Douglas, 22, who was shot in January 2006, said the hole her son had left “will never be filled”.
Diane Douglas, from Aberdeen, told the Evening Express newspaper: “We didn’t get proper closure.
“I think about him every day and think of things I want to say to him every day.
“That hole will never be filled. I want to see justice done for the lives that were lost.”
She added: “I want him (Tony Blair) to admit that it was illegal for a start and to admit that he did wrong.
“I would hope to see something come out of it, I would like parents to get compensation.”
The 19 Scottish soldiers who died in Iraq campaign and date of death:
Barry Stephen, of Scone, Perth and Kinross - 24 March 2003.
Alexander Tweedie, of Hawick, Scottish Borders - 22 April 2003.
James McCue, of Paisley, Renfrewshire - 30 April 2003.
David Shepherd, of Creetown, Dumfries and Galloway - 19 May 2003.
Jason Smith, of Hawick, Scottish Borders - 13 August 2003.
Russell Beeston, of Govan, Glasgow - 27 August 2003.
Andrew Craw, of Alloa, Clackmannanshire -7 January 2004.
Robert Thomson, of Bathgate, West Lothian - 31 January 2004.
Gordon Gentle, of Pollock, Glasgow - 28 June 2004.
Marc Ferns, of Glenrothes, Fife - 12 August 2004.
Kevin McHale, of Lochgelly, Fife - 29 October 2004.
Stuart Gray, of Dunfermline, Fife - 4 November 2004.
Scott McArdle, of Glenrothes, Fife - 4 November 2004.
Paul Lowe, of Dunfermline, Fife - 4 November 2004.
Allan Douglas, of Aberdeen - 30 January 2006.
Gordon Pritchard, of Edinburgh - 31 January 2006.
James Kerr, of Cowdenbeath, Fife - 28 June 2007.
Scott Kennedy, of Dunfermline, Fife - 28 June 2007.
Stephen Ferguson, of Lanarkshire -13 December 2007.