A murder investigation is under way with a large area cordoned off and officers making door-to-door inquiries. Gwent Police have arrested a 27-year-old man from the Manchester area, on suspicion of murder.
Neighbours of the family have spoken of an unnamed "wild-looking" man who lived in a tent in a field close to the family of three's address.
He is known to have argued with Kim Buckley in the weeks before the blaze in which she died, threatening to kill her.
"Kim was a feisty person who wasn't about to let herself be pushed around by someone," said friend Tania Brown, 26.
"But I know she did argue with the guy in question and he was later living in a tent in an open field which gives on to sheltered housing.