My experience is that as long as a "caveat" has been filed with respect to the probate of a given estate, it remains there unless there is a written stipulation and order by the person who filed it that it be removed, or an interested person under the Will being probated files a motion to have it removed after a hearing on the matter decided by the Probate Court.In your matter, if your sister will not voluntarily remove the "caveat", I would recommend that the executor or executrix of the estate file a petition to have it removed so that the estate can proceed in an orderly manner to be closed after assets are distributed.