Neighbours of the victims of the house fire in Cwmbran, Gwent, have spoken of their shock at the deaths.
Tania Brown, a friend of the Buckley family, told ITV Wales she "just wanted to cry" when she learned.
The victims were earlier named as 46-year-old Kim Buckley, her 17-year-old daughter Kayleigh Buckley and her six-month-old grand-daughter Kimberley Buckley.
Police have paid tribute to two residents who "valiantly and bravely" attempted to rescue them, but were forced back by the flames.
Chief Inspector Steve Corcoran described the fire as a "tragic and horrendous incident."
More top news
A man has 'potentially life-changing injuries' after acid was thrown over him after a screening of the movie Straight Outta Compton.
A leading sexual health clinic has apologised after mistakenly sharing the HIV positive status of hundreds of patients in an email.
Skeletons unearthed in a mass grave in Durham are the remains of Scottish prisoners of war, experts have found.