Ms Trumble claims she was unfairly dismissed
Heather Mills's former nanny has told an employment tribunal she was made to work long hours without extra pay.
Sara Trumble, 26, of West Sussex, is seeking compensation from Sir Paul McCartney's ex-wife, alleging unfair dismissal and sex discrimination.
She said she felt she was a hard-working and loyal worker but in return her former boss took advantage of her.
Ms Mills, a former model of Robertsbridge, East Sussex, was at the hearing in Ashford, Kent.
Ms Trumble, who lived with her family in Westfield, said that from April 2004 she was employed to look after Ms Mills and Sir Paul's six-month-old daughter from 10am to 6pm, five days a week, while the couple were still living together.
She said Mills "was really nice and genuine" at first.
However she soon found she was often expected to stay well into the evening while she waited for the couple to return home, without extra pay.
Ms Trumble also said that following the couple's separation in May 2006 her job changed further as custody of the little girl was shared between Ms Mills and Sir Paul.
Ms Trumble, who was paid £260 a week by Mills, said: "Heather was very bitter towards Paul.
"I was, I believe, a great source of comfort and support for Heather at this time."
'Lied under oath'
She also claimed the former model was unsympathetic towards her when she went through a difficult pregnancy, forcing her to accompany her on trips abroad.
Earlier the tribunal was delayed due to legal argument over whether information from the Mills-McCartney divorce proceedings should be used as evidence.
The tribunal was told such evidence was relevant because it showed Ms Mills had lied under oath at the High Court.
Tribunal judge Steven Vowles said it should not be used on the grounds of its late disclosure and lack of relevance.