Thanks Candace. From the diagram it indicates that the Queen's coffin was placed above Prince Philip's and adjacent to her mother's so it seems that order of death has been followed after all. Wonder why Prince Philip wasn't just placed in the vault after his funeral instead of having to deal with the burial of both coffins?

According to another website about the Chapel, the vault was originally constructed to accommodate three monarchs and their consorts so there should be room for Charles and Camilla when the time comes....if that is what they wish of course.