At about 06:17 BST on Sunday, police were called to the house in Sterncourt Road in Frenchay to what officers described as a domestic-related incident.
The caller said a man, whom they knew, had forced his way in to the house and was believed to have an explosive device.
The blast happened just after 06:30 BST, killing both Shaw and Kelly.
In a statement, Lee paid tribute to her “best friend” and “sister” who had been there at “every stage of [her] life”.
“You weren’t just part of my life you were part of my family,” she said.
“You were there when my first daughter Sienna was born, standing beside me in one of the most important moments of my life.
“That’s the kind of friend you were – always there, no matter what.”
