Who is entitled to appealing a decision of the Court or filing a motion for reconsideration?
"A person aggrieved by an order, judgment, decree or denial of a probate court made after this chapter takes effect, may, within thirty days after the entry thereof, appeal therefrom to the appeals court or, subject to the provisions of section ten
of chapter two hundred and eleven A, to the full court of the supreme judicial court. Said courts shall have like powers and authority with respect thereto as upon an appeal in any civil action." See M.G.L. 215 Section 9.
Also, note that a party may ask the court to relieve it from a final judgment (such as the judgment you describe) if there is newly discovered evidence or fraud, misrepresentation, or other misconduct of the adverse party, etc... See Mass. Civil Procedure Rule 60(b).