Rubuta ci gaba don wannan sakin layi - Petrova ya yi yaƙi a cikin Yakin Soviet-Finnish
kafin ya ba da kansa don yin aiki a cikin Jamus-Soviet War. Da farko ta yi aiki a cikin Rukunin na 4 na Sojojin Jama'ar Leningrad kafin ta shiga rukunin likitoci, duk da cewa ta tsufa da za a ɗauke ta. A watan Nuwambar 1941 an canza ta don yin yaƙi a matsayin mai harbi a cikin 1st Infantry Battalion na 284th Infantry Regiment na 86th Tartu Rifle Division, inda ta tashi ta cikin sahu zuwa babban jami'in (starshina). A cikin yakin Leningrad ta horar da wasu sojoji na Red Army a matsayin 'yan bindiga ban da shiga cikin yaƙi kai tsaye.