The mother of the three children from Gloucestershire apparently killed by their father spoke of her devastation.
Ruth Fuller, mother of Sam, 12, and his sisters Becka, aged eight, and seven-year-old Charlotte, released a short statement through Gloucestershire Police.
Mrs Fuller said: "I don't have the words to describe how I feel at the moment. All I would ask is that I be left alone to grieve for my family."
The bodies of the three children were discovered at a beauty spot near Shrewsbury, Shropshire. It is believed they died from knife wounds.
The body of their father Ceri Fuller, 35, was found nearby at the Poles Coppice on Pontesbury Hill. He is thought to have fallen from a cliff.
West Mercia Police have recovered a knife and one line of inquiry detectives are following is that Mr Fuller killed the children before taking his own life.
The force launched a murder investigation but described the deaths as a "tragic family situation" and are not looking for anyone else.
Detective Chief Inspector Neil Jamieson, who is leading the investigation, said: "I can disclose that a weapon has been recovered from the scene. Officers involved in the search found a knife in the vicinity of where the bodies were found. It will now be forensically examined."
Police are appealing for information about possible sightings of family Land Rover Freelander and its four occupants on Thursday.
Mr Jamieson said: "We believe this vehicle left Gloucestershire at some point last Wednesday evening or early Thursday morning and we are anxious to establish its movements since then, especially in the Pontesbury area. We believe it was in the Leominster area at around midday on Thursday before making its way up towards Welshpool later that day."
