Kristi Anne Abrahams has pleaded guilty to murdering her six-year-old daughter Kiesha in western Sydney.

Abrahams, 30, entered the guilty plea in the Supreme Court on Monday on what was expected to be the first day of her murder trial.

Kiesha Weippeart was reported missing from her Mt Druitt home on August 1, 2010.

Abrahams was charged with murder after human remains were discovered in bushland at Mt Druitt eight months later in April 2011 - on what would have been Kiesha's seventh birthday.