We have discussed this a lot on this forum. Personally I believe they are best qualified. She had a daughter and six sons and her husband was also a Romanov. By British succession laws, a sister would rule if there wre no sons, or if her brothers were deceased, such as Elizabeth I. So by that rule, Xenia is the prime candidate. I would think a female decendant of the direct line would be more official than a male descendant of an indirect line. Old Russian law stated no woman could inherit the throne, but the pretender Maria Vladimorovna is a woman, and has less credientials! If I were looking for the true heir to the throne, it would be a descendant of Xenia and Sandro's oldest son, Andrew/Andre.