She had a 60-year-long career as a professional actress (with debut 1889) before she made her last performance in 1949 as Julia Hylténius in the successful staging of the comedy The Barons Will by Hjalmar Bergman.

She studied at the Royal Dramatic Training Academy 1886-1889 and in 1891 appeared as Queen Gertrude in Hamlet, a performance that established Lundequist's reputation.

Notable performances by Lundequist include the title role in Schiller's Maria Stuart (1910), Goneril in Shakespeare's King Lear (1908), Béline in Molière's The Imaginary Invalid (1897), the title role in Maeterlinck's Monna Vanna (at the Swedish Theatre 1912), the title role in Hjalmar Söderberg's Gertrud (1907; original staging), Tora in Paul Lange and Tora Parsberg by Bjørnson (1922), Mrs Alving in Ibsen's Ghosts (1938) and Mrs. Dowey in The Old Lady Shows Her Medals by J.M.

In 1947, at age 76, she had critical success with portrayal as the Dutchess of York in Richard III, directed by Alf Sjöberg and as Maria Josefa in Lorca's Blood Wedding.

Lundequist played a supporting role in the 1955 Swedish drama film Giftas (based on a novel by August Strindberg), as the old Royal Highness, at age 84.