The girlfriend of Becky Watts' stepbrother Nathan Matthews, Shauna Hoare, has also now been charged with Becky's murder.
Becky, 16, went missing from her home in the Crown Hill area of Bristol on 20 February (2015) taking her tablet, laptop and phone but no change of clothes. After a huge police search her body parts were found at a nearby house in Barton Hill 11 days later on 2 March.
Becky's stepbrother Nathan, 28, was initially charged with her murder and his lover Hoare, 21, with perverting the course of justice and other charges.
However, on 22 June, Avon and Somerset Police said Hoare will also be charged with murder following specialist forensic examinations of Becky's body.
Hoare and Matthews are also accused of perverting the course of justice, conspiracy to commit false imprisonment, preventing Becky's lawful burial, possession of an offensive weapon, plus four counts of making indecent images of children (this is not related to Becky's death).
Matthews, a delivery driver, faces two other charges not related to Becky: sexual assault and voyeurism.
Four other people, Karl Demetrius, Donovan Demetrius, Jaydene Parsons and James Ireland are all charged with assisting an offender.
Detective Superintendent Liz Tunks said: "Our thoughts and sympathies are with Becky's family. This has been a very difficult time for them and they have had to endure yet more pain as we have worked to understand the full circumstances surrounding her death.
"Our continuing investigative work in this case demonstrates our determination to explore all avenues even after suspects have been charged. This has been a meticulous and exhaustive investigation. We are determined to find answers for Becky's family and bring all those who played a part in her death to justice."
"I would like to thank the local communities in St George and Barton Hill for their patience and co-operation as this investigation continues."
Rachael Scott, head of the CPS South West Complex Casework Unit, said: "Following receipt of a full file from Avon and Somerset police, the CPS has authorised a number of additional charges against both Nathan Matthews and Shauna Hoare. Most significantly there is now sufficient evidence to charge Shauna Hoare with the murder of Becky Watts.
"Proceedings are now ongoing and the defendants have the right to a fair trial. It is very important that there should be no reporting, commentary or sharing of information online which could in any way prejudice these proceedings."
Matthews and Hoare will have the additional charges added to their indictment at their next court appearance at Bristol Crown Court on 4 August.