Tania Chernova was an American, a New Yorker of Russian descent. She was nineteen years old and had dreamed of becoming a ballerina. She was in Russia at the start of the war to help rescue her grandparents, but ended up fighting on the side of the partisans in her native Belarus when the Germans slaughtered her grandparents. After serving with the partisans, she made her way to Stalingrad, determined to kill as many Germans as she could. Many of the savage German reprisals led her to dehumanize the enemy. She called them sticks, fit only for breaking.
Reaching Stalingrad, her and her companions evaded the Germans by using the sewer system, trying to reach a Russian unit. They got lost in the maze and after hiding their weapons, emerged behind enemy lines and joined a chow line at a Wehrmacht field kitchen for food. Fresh from the sewers, their odors attracted the attention of the Germans. A Russian collaborator claimed they were working for him. Despite his help, she made no attempt to hide her loathing for him or any other Hiwi (Hilfsfreiwilliger, or volunteer) working for the Germans. The Hiwi, to her, were worse than the Germans. She was determined to kill this man when she had to opportunity.
She eventually became a student at the special school for snipers headed by Vassili Zaitsev, and they fell in love and had an on going love affair.
Tania continued her vendetta against the Germans. It is reported that she took part in a raid on German headquarters, where she set explosives and picked off guards by rifle fire. It has also been reported that she killed an SS security agent in hand-to-hand combat.
She was eventually wounded in the abdomen and awoke in a field hospital. She recovered from a surgery that would leave her unable to bear children. This is when Vassili and Tania were separated, and never saw one another again. She was 22 years old. (http://www.snipershide.com/sniping/chernova.html)
The love affair between Tania Chernova and Vassili Zaitsev was certainly for real. But she was wounded during an attempt to find and snipe Friedrich Von Paulus, the commanding General of the German 6th Army, when the female sniper ahead of her stepped on a land mine - not during an evacuation as the movie depicts. Severely wounded, Tania was carried back by her lover, Zaitsev, but that was the last either ever saw of one another. While recuperating in the hospital, Tania heard that Vassili was killed by a mine toward the end of the offensive and did not learn anything to the contrary until 1969...
Tania loved Vassili, and she was wrongly told he had been killed. Tania went into a severe depression over her loss and her own wounds. In 1969, she learned he survived when a foreign reporter asked her about her time in the Hares. She asked how this man knew of her, and he told her that Zaitsev had spoken of her. After this interview, Tania thought that Vassili had never come back for her, and her heart was broken again. Zaitsev did try to find Tania, but records were scarce in Russia after the war. He lost track and, saddened, went on his way.
There was no love triangle involving Danilov as shown in the movie. She never discussed becoming and interpreter with Danilov. Also, Tania never knew Sasha and was not Sasha's neighbor.