The court of appeal judge Lady Justice Thirlwall has been appointed to lead the public inquiry into Lucy Letby’s murder of seven babies in an NHS hospital. The health secretary, Steve Barclay, described Thirlwall as “one of the country’s most senior judges” as he announced her appointment in a statement to the House of Commons on Monday. Thirlwall was called to the bar in 1982 and became a part-time judge in 1998. She was made a senior barrister the following year. She was appointed as a high court judge in the queen’s bench division in 2010 and to the court of appeal in 2017. In 2016 she was appointed to the Sentencing Council, which produces guidelines on sentencing. She was the presiding judge in the 2013 case of Mick and Mairead Philpott and Paul Mosley, who together plotted to set fire to a Derby home, which led to the deaths of six children. Barclay said he had told Thirlwall that the families of Letby’s victims were hoping that the inquiry would be split into distinct sections to avoid having to wait until its completion to get any answers. “I have raised with Lady Justice Thirlwall that the families should work with her to shape the terms of reference,” said Barclay. “We hope to finalise these in the next couple of weeks so the inquiry can start the consultation as soon as possible. “I have also discussed with Lady Justice Thirlwall the families’ desire for the inquiry to take place in phases so it provides answers to vital questions as soon as possible.” Barclay confirmed, as announced on Wednesday, that the Letby inquiry would be on a statutory footing. The government had initially said it would be a non-statutory inquiry, citing the desire for a shorter timescale, but changed its mind in the face of growing criticism that without the necessary powers to compel people to give testimony under oath or force the disclosure of documents it would be unfit for purpose. Giving the inquiry statutory powers will mean that former and current staff of the Countess of Chester hospital trust, where Letby worked as a neonatal nurse, could be obliged to appear. Barclay told the Commons that the change to a statutory inquiry came after he arranged for the police liaison officer to meet the families of Letby’s victims to discuss with them the form the inquiry should take. He said their wishes were clear. Barclay told MPs: “This inquiry will examine the case’s wider circumstances, including the trust’s response to clinicians who raised the alarm and the conduct of the wider NHS and its regulators.” Thirlwall was educated at St Anthony’s Girls’ Catholic academy in Sunderland. She told the Times her first job was a Saturday shift on the checkout at her local branch of Littlewoods. She said her most inspiring book was I Know Why the Caged Bird Sings, the first volume of Maya Angelou’s autobiography, because the author faced “discrimination and adversity of every kind with profound strength and determination”.