Karl and Donovan Demetrius, both 29, Jaydene Parsons, 23, and James Ireland, 23, were charged with assisting an offender earlier.
All were remanded in custody after a short hearing at Bristol Magistrates' Court.
Becky's stepbrother, Nathan Matthews, 28, appeared in court earlier charged with her murder.
Karl and Donovan Demetrius, and Ms Parsons, all of Barton Court, Bristol, and Mr Ireland, from Avonmouth, will appear at the city's crown court on 26 March.
They all face a single charge of disposing or concealing Becky's body parts with the intent "to impede the apprehension or prosecution of Nathan Matthews".
A fifth person - a 23-year-old man also arrested on 2 March - was released without charge.
The 16-year-old's stepbrother, of Warmley, Bristol, appeared at the city's crown court via video link earlier, charged with her murder.
He was also remanded in custody to appear at crown court on 26 March.
Mr Matthews' girlfriend, Shauna Hoare, 21, appeared alongside him at Bristol Magistrates' Court on Thursday charged with perverting the course of justice.
She will appear before the crown court on 2 April.
Becky was last seen on 19 February and was reported missing the following day.
The discovery of her body came after an extensive search of various locations across Bristol.
Four people have appeared in court accused of helping to hide or dispose of teenager Becky Watts' body parts.