Maës sought an apprenticeship at the Royal Danish Theatre after appearing there in Carl Erik Soya's Natteherberget, but was turned down.

She played starring roles in several family films adapted from the popular Morten Korch novels, the first of which, The Red Horses, became the biggest box-office success in Danish cinema.

In 1966, she caused a public reaction when she went against her usual movie persona, playing against type in the role of a prostitute named Lucy in the black comedy Galgenhumor (Gallows Humor).

Maës' portrayal of the drunken and grotesque mother of a small-time criminal brought her the Bodil Award for Best Actress.

She again won the Bodil Award in 1982 for her performance as an overlooked but fantasy-filled retiree in Erik Clausen's drama Felix.

Maës is noted for a number of supporting roles on television series including the sister, Jette on Rundt om Selma, the mother in the adaptation of Pirandello's Six Characters in Search of an Author, the subdued Lilly Lund on Matador, and Mrs. Zachariasen on the TV mini-series The Kingdom.