Gill Hicks, 45, who was on the Tube train blown up by suicide bomber Germaine Lindsay at Russell Square on July 7, 2005, gave birth six months ago to Amelie, her daughter with husband industrial designer Karl Falzon.
"Becoming a mum has been wonderful for me," said Dr Hicks, an author and motivational speaker.
"It's one of the things which has kept me going, it has changed my life."
Gill, who was awarded an MBE for her work in promoting peace, was not expected to live after being injured in the Piccadilly line train explosion. She soon became one of the most recognisable faces of the attacks after leaving her job in public relations and setting up the Making a Difference for Peace charity.
Amelie was born in Adelaide in January and is a first child for Gill and partner Karl Falzon.
The couple said at the time: "Amelie is a precious miracle and a symbol of all that was pure and innocent in life. We celebrate you, Amelie, for you are the embodiment of new beginnings, of brilliant intention and all that is wonderful and beautiful."
Dr Hicks flew from her native Australia to attend the second annual 7/7 memorial lecture in Tavistock Square, site of the suicide bombing in which 13 people died.