Jacqui Porter, 40, from Ruislip, allegedly treated family and friends to designer jewellery, luxury holidays and lavish parties.
She was bankrolled by her Scottish husband, Gerald Porter, 52, who is accused of cheating his company, Greenfield Property Management Limited, out of millions.
The family boasted a fleet of cars and jetted across the globe, taking luxury holidays to Bermuda, Mexico, Dubai and New Zealand, Southward Crown Court heard. But Jacqui denies any knowledge of her husband's alleged fraud.
Her niece, Alice Moss, recalled seeing the family mansion and its 'park-like gardens' in Harefield when she was aged 10.
She told the court: “She used to buy us a lot of things. Every time we went there we would go on dinner trips to nice restaurants. At Christmas we always got nice gifts, we went on holidays. Me and my sister both received Tiffany bracelets for Christmas one year as well as Louis Vuitton purses.”
She added: “Two of their friends I believe were quite famous people - they used to come to the house. I think I saw them once at the house and they they used to speak about them quite a lot.”
When asked who the stars were, she replied: “Gabby Logan and, I can't remember what her husband's name was.”
Jurors previously heard that rugby fan Gerald sponsored the radio presenter's husband, Wasps winger Kenny Logan, using the stolen money, without the Logans' knowledge.
Jacqui claims she knew her husband was 'cooking the books' in a tax-evasion scam but not that he stole money from his employers.
Jacqui Porter, of Cherwell Way, Ruislip, denies a single count of concealing or converting the proceeds of crime.
The trial continues.