SAN FRANCISCO -- A former bookkeeper and financial assistant to novelist Danielle Steel has pleaded guilty in federal court in San Francisco to charges stemming from the embezzlement of more than $400,000 from the best-selling author.

Kristy S. Watts, 47, of San Rafael, pleaded guilty before U.S. District Judge Vaughn Walker on Sept. 24 to one count of wire fraud and four counts of tax evasion.

In a written plea agreement filed in court, Watts admitted that between 2003 and 2008, "I embezzled and stole more than $400,000" from the employer.

The employer is identified in court documents only as Employer A, a female who formed an entity known as TPA to coordinate her expenses, including household and travel expenses.

But in a separate case, a plaintiff by the name of Danielle Perkins, of San Francisco, filed a civil lawsuit against Watts in Marin County Superior Court on Sept. 24, the same day as the guilty plea.

Perkins is Steel's married name; she was married to financier Tom Perkins for about two years in the late 1990s.

The civil lawsuit alleges that fraud and "continuous and repeated thefts" by Watts cost Perkins $2.7 million. It states that Danielle Perkins did business as TPA Co. and that Watts was controller of the company.

Both the criminal case documents and the civil lawsuit say that Watts worked for TPA from 1993 until she was fired in December 2008.

Watts, who is also known as Kristy Siegrist, said in the federal plea agreement that she embezzled from her employer in three ways.

Those were: depositing checks made out by her employer for "cash" to her personal account; using the employer's credit card reward points to buy airline tickets and gift cards for Watts and her family; and arranging for a payroll processing company to pay her more than she was due, according to the plea agreement.

Watts said in the plea agreement that her responsibilities included bookkeeping, payroll, accounting and petty cash duties and managing some bank accounts.

Watts is due to be sentenced by Walker on Feb. 4. Prosecutors and Watts agreed in the plea bargain to a sentence of two years and nine months in prison; if the judge gives a different sentence, either side would be entitled to set aside the guilty plea and go to trial instead.

Watts was accused of wire fraud and tax evasion for the years 2005 through 2008 in criminal charges filed by federal prosecutors on Aug. 19. She gave up her right to be indicted by a federal grand jury and pleaded guilty to all five charges.

The Marin County Superior Court civil lawsuit says that Danielle Perkins "first learned of possible irregularities in (Watts') handling of bank and credit cards and money belonging to plaintiff" in November 2008. After an investigation, Watts was fired on Dec. 19, the lawsuit said.

Danielle Steel is associated with TPA Co. in other public documents, including records of contributions made to the Democratic Congressional Campaign Committee in 2004 by Danielle Steel of San Francisco, who is identified as an author employed by TPA Co.

Steel has written 76 books and there are 580 million copies of her books in print, according to her Web site.

Watts' defense attorney, Anthony Brass, and Danielle Perkins's lawyer in the civil lawsuit, Cecily Waterman, were not immediately available for comment Monday.