Lady Mayoress

Noun

 * 1) The wife or other official female consort of a Lord Mayor
 * 2) * 2016 "Our Work" Leeds Children's Charity website:
 * In 1904, Helen Currer Briggs, the Lady Mayoress of Leeds paved the way to providing free holidays for young children whose family income was less than a single pound. Since then it has been the right of every new Lady Mayoress to become the president of the charity.

Usage notes
A female holder of the office of Lord Mayor is called a or.