NSW mum behind bars over toddler's murder

A woman accused of murdering her two-year-old daughter is behind bars after facing a Sydney court.

The 27-year-old mother did not apply for bail, and it was formally refused, when she appeared at Penrith Local Court via videolink on Wednesday.

She was charged with the little girl's murder after the toddler's body was discovered in the bathtub of a home at Miller in southwest Sydney just after midday on Tuesday.

Police will allege the girl was murdered at some stage between early Saturday morning and Tuesday afternoon.

The mother was charged at Katoomba, in the Blue Mountains, on Tuesday night.

A male supporter covered his face and ran to his car to avoid the media after the woman's court appearance.

Her case was adjourned to Campbelltown Local Court on November 9.