A judge has praised two teenagers who testified in court against their relentlessly cruel mother as he jailed the woman for blighting her family's lives.

Linda Clappison, who has shown no remorse since her arrest, was given two concurrent terms of 18 months for starving, beating and torturing her younger son and daughter. According to her children, her character changed "disastrously" after a meeting with a purported fortune teller.

A trial at Hull crown court heard how her son, Andrew, who is now 18, was "treated like a dog", forced to sleep without bedding in rooms so cold he suffered frostbite. Her daughter, now 13, told a jury her mother had shaved her hair off five times to humiliate her at school for wanting to look pretty. Both children were made to work long days at travellers' market stalls ? the girl when she was aged under 10 ? and further punished for things they had not done.

The abuse went on for six years after Clappison's supposed transformation from a caring, even over-protective mother into an obsessive dependant of the fortune teller's who hated her own children, whom she still rejects as liars.

Judge Michael Mettyear, the recorder of Hull, told her this change was "her loss, not theirs", adding: "It is sad that seeing your children in court giving evidence did not in any way melt your heart. It is sad that your initial period in custody has not changed you.

"Custody is inevitable: you have blighted the lives of these children.

"Nobody sitting through the trial could have failed to be moved and impressed with them. They are the sort of children that any thinking parent clearly would admire. They were measured, sensible and pleasant. It is a credit to them, rather than to you, that they have survived what you put them through, and made remarkable progress."

Mettyear added: "You say that they and your two older children are liars and you would not consider reconciliation with any of them, ever. In my view it is your loss, not theirs. They are super children."

The judge said that he could not be certain that Clappison's change of character was because of the fortune teller, Liz Smith, as the children and the prosecutor, Mark McKone, alleged during the trial last month. Smith did not give evidence, and the recorder said: "I have a rule not to criticise those people who do not appear before me. But I am satisfied that something changed, and it changed with disastrous consequences. Something went very, very badly wrong in your life and in your mind."

Andrew Clappison told the jury that his mother cooked herself hot meals at their home in Keyingham, east Yorkshire, while feeding him and his younger sister on chocolate spread sandwiches and leftovers from the travellers who ran the market stalls. She evaded calls from the children's schools, where attendance for both of them fell below 50%, and fooled a social worker who arranged a visit, he said.

"She unlocked my room, got my toys out and laid them on the floor. She made me come downstairs and put biscuits out and made it look like happy families."She forced us to have cold baths, which was the worst. It was a bad punishment, and she knew it was. She is an evil person. We were treated like dogs, basically."

His sister told the jury in video evidence about the cold baths, and added: "Some days she would not give us anything to eat. She had locks on the doors to keep us locked in."

McKone told the sentencing hearing that Clappison's older children had left home as soon as they could, and were then barred from seeing Andrew and his sister until their mother's arrest. He said: "Linda Clappison has washed her hands of all four children. That shows a coldness that is not only unusual in a mother, but also demonstrates that she is capable of being cruel."

Clappison stood in the dock wearing a cream sweater with a grey-and-pink diamond pattern and a blue necklace, with her hands behind her back throughout the sentencing. She showed no emotion as the case was summarised, during the judge's comments, or as she was taken down to start her sentence.