Born in 1926, Kalugina was aged 15 when Germany invaded the Soviet Union in 1941, at which time she was working in a munitions factory. Shortly after the invasion she joined the Komsomol (Communist Youth League) and in 1943 she was accepted into a Komsomol sniper school. Although she initially struggled with the training, Kalugina credited her graduation from the school to the patience of her squad commander.
Kalugina was sent to the front lines in March 1944 where she joined the 3rd Belorussian Front. Aged 17, she operated in a sniper/spotter team with a girl who she had trained with, Marusia Chikhvintseva. Her usual weapon was a Mosin-Nagant rifle with a PU scope, with which she engaged enemies at distances from as close as 200 metres to as far as 1200. She described her objective as eliminating key targets such as enemy commanders and machine gun emplacements, making one shot per day from a heavily camouflaged position and then returning to base at night.
Kalugina survived the war, although her partner, Chikhvintseva, did not. There is no account of her life following the end of the war.
An interview with Kalugina describing her experiences of her wartime experiences in detail can be read here.