Question: When was Dora Maar in a relationship with Picasso?
About the article "The Weeping Woman", section "Dora Maar".

Candidate passages:
Tete de femme (Dora Maar) is a plaster-modelled, bronze-cast sculpture by Pablo Picasso.
Dora Maar, Picasso's lover at the time, was the subject of the work which was originally conceived in 1941.
Four copies of the bust were cast in the 1950s, several years after the relationship ended. 
Marie-Thérèse Walter (13 July 1909 – 20 October 1977) was the French mistress and model of Pablo Picasso from 1927 to about 1935, and the mother of his daughter, Maya Widmaier-Picasso.
Their relationship began when she was seventeen years old; he was 45 and still living with his first wife, Olga Khokhlova.
It ended when Picasso moved on to his next mistress, artist Dora Maar.
In Picasso's paintings, Walter appears as blonde, sunny, and bright, as in "Le Rêve" (1932), in contrast to his darker portrayal of Dora Maar, whom Picasso painted as the tortured "weeping woman". 
Dora Maar was Picasso's mistress from 1936 until 1944.
In the course of their relationship, Picasso painted her in a number of guises, some realistic, some benign, others tortured or threatening.
Picasso explained:""For me she's the weeping woman.
For years I've painted her in tortured forms, not through sadism, and not with pleasure, either; just obeying a vision that forced itself on me.
It was the deep reality, not the superficial one.
""""Dora, for me, was always a weeping woman... And it's important, because women are suffering machines.""
Dora Maar au Chat ("Dora Maar with Cat") is a 1941 painting by Pablo Picasso.
It depicts Dora Maar, the painter's lover, seated on a chair with a small cat perched on her shoulders.
This work is one of the world's most expensive paintings. 
The canvas (50 ½ by 37 ½ inches / 128.3 cm by 95.3 cm) was one of many portraits of Dora Maar painted by Pablo Picasso over their nearly decade-long relationship.
Picasso fell in love with the 29-year old Maar at the age of 55 and soon began living with her.
This painting was done during the year 1941, when the Nazis were occupying France.
In the 1940s, the painting was obtained by Chicago collectors Leigh and Mary Block.
They sold the painting in 1963 After that, the painting was never shown until the 21st century.
During 2005 and 2006, "Dora Maar au Chat", then owned by the Gidwitz family of Chicago, was shown worldwide as part of Sotheby's exhibitions in London, Hong Kong and New York.
It came up for sale in an auction of Impressionist/Modern works held at Sotheby's on May 3, 2006 in New York and making it the second-highest price ever paid for a painting at auction.
An anonymous Russian bidder present at the New York auction won the work with a final bid of US$95,216,000, well exceeding the pre-auction US$50 million estimates.
The identity of the bidder, who spent more than US$100 million in total, and purchased an 1883 Monet seascape and a 1978 Chagall in addition to the Picasso, was a topic of much speculation.
Apparently a novice bidder, though possibly acting as an agent for a more well-known collector, the anonymous buyer may have been unknown at the start of the auction even to Sotheby's officials.
As of mid-2007, the ownership of the "Dora Maar au Chat" is still unknown to the general public, although rumors have focused on the Georgian mining magnate and current Prime Minister of Georgia Bidzina (Boris) Ivanishvili, who sold his Moscow bank a week before the auction for $550 m.