Police suspect the fire which claimed the lives of eight-year-old Alliyah Primus and her aunt, Nolene Niesha Gopaul, on Friday morning was deliberately set.
The blaze was set at the front and back doors trapping the family inside, police said.
Investigators said relatives have disclosed information which led officers to suspect arson.
Fifteen persons, including six children, live in the two-storey concrete house. All escaped but the little girl and her 40-year-old aunt.
The remains of the Fifth Company Baptiste School pupil and her aunt were found in the kitchen of the family's home at Indian Walk, Moruga.
Relatives said the girl and her aunt were asleep on the same bed when fire broke out at around 2am.
Gopaul's father, Lincoln Elvin, said he was asleep with his wife, Sumintra Gopaul, in an apartment at the front of the house when he heard a loud noise.
Elvin said he looked outside and saw flames coming from the house where his children and grandchildren were sleeping.
“The current went and I dropped the keys to the gate. I ran back and broke open a window to get out. I started calling everyone and asked who missing. They said Alliyah and Niesha missing. We could not find them. After the fire officers out the blaze we saw them lying in the kitchen,” he said.
The child's mother, Nicole Gopaul, was not at home when the fire started. She was spending the night in Oropouche, relatives said.
Gopaul was inconsolable when she returned home on Friday.
Her twin sister, Nikiesha Mitchell, said her sister was a single mother who worked hard to raise her only child.
Mitchell said, “Right now we will say it is a fire and deal with our losses. But it is much more than that. We will talk about that after. The fire was set at both doors and they were trapped inside.”
She said her family lost everything in the blaze and would stay at the homes of relatives until they can rebuild their home.