A woman has been charged in relation to the murder of Sydney teenager Brayden Dillon.

A woman charged with the murder of Sydney teenager Brayden Dillon has been refused bail in court.

Sophie Massie, 30, did not appear at Blacktown Local Court on Thursday where her lawyer Nick Blaker did not apply for bail and it was formally refused.

Her 26-year-old alleged accomplice Conrad Craig, who is accused of shooting 15-year-old Dillon in the head after bursting into his home almost three months ago, was also refused bail when he faced the same court on Tuesday.