A mother whose estranged husband molested their toddler in foster care says the British Columbia government's decision to appeal a scathing court ruling in her favour is "cruel" and "sadistic."

"I think it's completely rude, and inhumane for them to go on against little children who have been hurt so terribly," said the mother, known only as J.P., in a statement.

Children's Minister Stephanie Cadieux defended the move saying the decision was not about the family involved, but about every family that the ministry may interact with in the future.

However, the province's Representative for Children and Youth, Mary Ellen Turpel-Lafond, sided with the mother.

"I fail to understand how a case about her is not about her and her children. It's pretty hard for the government to say 'please don't take this personally, but we intend to totally quash this decision.'"

The province filed documents on Friday to seek "clarity" from the B.C. Court of Appeal in a ruling that found social workers knowingly violated a court order and allowed unsupervised access to a father who had sexually abused his kids.

The mother says the Ministry of Children and Family Development has been hurting her family since 2009, when it falsely accused her of being mentally ill and seized her children.

"What they have done for six years and now are continuing to do is cruel and sadistic. Like the people running the MCFD. We are suffering because of them."

Appeal in public interest

A B.C. Supreme Court judge ruled last month that the ministry showed "reckless disregard" when it failed to investigate the children's claims that their father had sexually abused them.

The judge also found that because ministry employees had acted in bad faith, immunity from liability under the Child, Family and Community Service Act does not apply.

J.P. and her estranged husband, identified as B.G., have four children born between 2002 and 2008.

Justice Paul Walker ruled in a custody trial in 2012 that B.G. had sexually abused his three eldest children. In his ruling last month, he found the man had also molested his youngest child while the girl was in foster care.

The notice of appeal filed Friday is sealed to the public as it includes family members' full names.

Cadieux, who declined interviews on Friday, said the appeal will not impact a former senior civil servant's review of practice and policy in the ministry. The review by Bob Plecas was announced last month after the Opposition New Democrats grilled the minister in the legislature about the case.

Instead, the justice ministry said in a statement that the finding that social workers in the case acted in bad faith has serious consequences for individual employees and others who perform the crucial public function of child protection.

"B.C. government lawyers advise me there is reason to believe the trial judge erred in a number of areas, and an appeal is warranted," she said in a statement.

Cadieux said any staff concerns that arise from the investigation will be examined by a separate human resources review.

Family not given advance notice

J.P.'s lawyer, Jack Hittrich, said he was "greatly disappointed" that he did not receive a copy of the appeal ahead of time. He said he could not comment until he had read the document.

Turpel-Lafond says this appeal is going to be traumatizing for the family, especially as they had no advance notice that it would be filed.

"There is always an opportunity to make things right, but first you have to accept what may have gone wrong," she told CBC. "Clearly today there is no acceptance by government that there was anything inappropriate or wrong in terms of the treatment of J.P. and her children."

The government has 90 days to file its legal arguments.

"This is one of most horrific cases and it will continue," said Turpel-Lafond.

"It's important to start make things right and there may be disagreements on the extent of their liability or legal tests and so forth ... but when will we repair relationships? It's clear now that there is no possibility of repairing relationships for many, many years to come and children will have to grow up in B.C. under that cloud."