Just to add a few bits:
1. The guideline would be 20 years due to their ages. The judge added on 10% for her due to her increased role in the planning and her ongoing lack of remorse, including creating a new ‘kill list’ for staff where she is being held.
2. The sentence is a minimum, they will not be released until they are deemed to no longer be a threat to society. In her case, the judge even said there is significant doubt she will ever be ‘safe’ for release. They will need to prove their remorse and rehabilitation before being released, and whilst they’re still ultimately young people with the ability to change, she will need to take full responsibility for her actions as will he.
3. They will be on licence for life if ever released. A further arrest could easily see them sent straight back to prison. Even without, if they ever want to go on holiday they need to get permission, if they want to even move within the UK they need to get permission. They will need to check in with police at regular intervals for the rest of their lives. The amount of time they spend in prison might ultimately never be ‘enough’ but equally they will never be ‘free’.