A HOUSEKEEPER who stole antiques and art including a Picasso sketch from a dowager Countess while working as her personal assistant was warned this week to prepare for jail.

Kim Roberts, aged 58, of Lower Church Street, Colyton, Devon, had pleaded guilty at an earlier hearing to stealing from Dowager Countess Bathurst, of Cirencester, Glos, and on Thursday at Gloucester crown court she admitted three more charges – including burgling the countess's London home.

The charge Roberts admitted at a hearing last year was that between April 29and May 24, 2013 she stole art and antiques belonging to the dowager countess.

At that time she maintained she was guilty on the basis that the property was put into her car by mistake.

On Thursday her barrister Simon Burns said she now abandoned that basis of plea and fully accepted her guilt. She went on to admit three charges she had previously denied.

These were: burglary of the dowager countess's home in Lennox Gardens, London, and theft of antique vases of unknown value between April 30 and August 20, 2013; theft of a Volvo X90 car from interior designer Emily Olympitis on October 21, 2012; and fraud between September 1, 2011 and December 31, 2011 by dishonestly telling Holland Park Staffing – an agency which provides domestic household staff such as butlers and nannies – that she was born in 1958.

However, she maintains her denial of three other charges: theft between September 30, 2011 and June 1, 2012 of a TV, DVD player, a blanket and a sheet belonging to John and Arabella Duffield; possession of criminal property – a Mont Blanc pen, clothing items, and accessories – between September 30, 2012 and June 1, 2014 knowing they were the proceeds of criminal activity; and theft of antiqiue silver hairbrushes belonging to Lady Juliet Worsley between December 1, 2012 and Janaury 31, 2013.

Mr Burns told the court he had spoken to the prosecution and believed that Roberts' guilty pleas would be acceptable and that the other charges would not be proceeded with.

Judge Jamie Tabor QC gave the prosecution 24 hours to notify the court if that is correct.

He bailed Roberts until May 7 on the basis that her pleas would be acceptable and he ordered a pre-sentence report on her from the probation service.

He warned her: "I don't want you to be under any illusions about the sentence you will receive. You should make arrangements prior to that date on the basis that you are going to be away for some time."

At an earlier hearing the court was told Roberts worked as a personal assistant for Gloria, the Dowager Countess of Bathurst, and had allegedly stolen precious paintings, antique vases and silver and pewter plates worth a total of £500,000.

The Dowager Countess is the widow of the eighth Earl Bathurst, Henry, who died in 2011 aged 84.

Their son Allen, formerly Lord Apsley, is now the 9th Earl and lives in the Mansion House, Cirencester Park with his wife Sara.

The Bathursts are one of England's oldest families, originating from Sussex where they owned Bathurst Castle until they were dispossessed of their lands by Edward IV in 1463, after siding with the Lancastrians in the War of the Roses.