Me. Rev. Stat. tit. 18-C, § 2-212

The right of election may be exercised only by a surviving spouse who is living when the petition for the elective share is filed in the court under section 2-211, subsection 1. If the election is not exercised by the surviving spouse personally, it may be exercised on the surviving spouse's behalf by the surviving spouse's conservator or agent under authority of a power of attorney.