By Martin HickmanRebekah Brooks did not know that Glenn Mulcaire was on a £92,000-a-year contract with the News of the World, she told the phone hacking trial today.Speaking about the paper's annual £30 million editorial budget when she was editor, Mrs Brooks said that she would approve big buy-ups such as securing the rights to David Beckham's autobiographies and approving the £2 million spent on the Sarah's Law campaign against paedophiles.But she added that she knew nothing about contributor payment requests made by departmental heads to pay those who worked for the paper, including Mulcaire, a specialist phone hacker.She have heads of individual departments a high degree of autonomy over their own budgets, provided they stayed within them, she told the Old Bailey. If they did not stick within those budgets, she said they would be asked to see the paper's managing editor, Stuart Kuttner.Asked by her counsel, Jonathan Laidlaw QC, whether she was aware of the £1,000-plus weekly payments to Mulcaire, Mrs Brooks replied: "The small sums, if they were paid within the weekly spending limit, they wouldn't have come to me."Anyone breaking the departmental spending limits would be in the Managing Editor's office and maybe I would be brought in by week three [of heavy overspending]"Asked whether she would have any involvement in the weekly expenditure of different desks, Mrs Brooks - who edited the NoW between May 2000 and January 2003 - replied: "None."Mr Laidlaw asked her: "Would you know anything about that [Mulcaire's] contract at the time".Mrs Brooks replied: "No".She explained that journalists closely guarded the source of their stories, saying: "There are all kinds of sources. Journalists are very protective of their sources and keep them to themselves... it's ingrained in a journalist to protect confidential sources."She told the court: "It was quite normal to have private detectives working on the paper... They would be helping in the main tracing people who were difficult to find."Asked whether she would expect their work to be drawn to her attention, Mrs Brooks said: "No, particularly. Obviously there were occasions when I knew: Sarah's Law."I remember we used quite a few private detectives during Sarah's Law. I know this because I was very involved in Sarah's Law."It's very difficult to trace convicted paedophiles because all you had to go on sometimes was a court report when they were sentenced."Mr Laidlaw apologised to Mrs Brooks for having to broach her relationship with her NoW deputy editor Andy Coulson, which the prosecution raised as evidence that they shared work information. First, Mr Laidlaw asked the former redtop editor about her relationship with the actor Ross Kemp.Mrs Brooks said she had met Mr Kemp in 1995 and had undergone fertility treatment in 2001 and 2002 in a fruitless attempt to have children with him.She said that she and Mr Kemp had been working "incredibly long hours in completely different industries"She went on: "The war in Iraq started pretty soon after I became editor [of the Sun] and we were doing 4am, 5am editions..."It was "not true" that she and Mr Coulson had had an affair for a six year period, she told the court, explaining that they had been "close" in 1998, "intimate again" between 2003 and 2005 and briefly intimate again in 2006.Referring to an unsent love letter to Mr Coulson found on her computer, dating from February 2004, she told the jury it was probably not a good idea to sit down at a computer after drinking several glasses of wine.Mrs Brooks said: "I think as many people know my personal life was a car crash for a number of years."However, she said that she had met her new husband Charlie in 2007 and he had agreed to marry her despite knowing that having children would be difficult. After unsuccessfully trying IVF treatment, she told the court, her surrogate daughter Scarlett was born in January 2012.Mrs Brooks denies conspiracies to hack phones, pay public officials and pervert the course of justice.