Sarenka escaped to eastern Poland ahead of the German advance, together with her sister Ruth. She initially arrived in
Kaidani, which at the time was under the
Russian control, joining Ha-Manof Kibbutz, and eventually relocating to
prewar Wilno (Vilna) and joining the Hashomer Hatzair Kibbutz there. With her good education, she immediately adopted an important role in
kibbutz life. She lived in Vilna with her partner, Moshe Kopito who himself was a close friend of Mordechai Anielewicz; the two men had joined the movement together much earlier. On 22 February 1941, Sarenka's daughter Maya was born. On 22 June 1941 the German army attacked the Soviet positions in eastern Poland under the code-name
Operation Barbarossa. Sarenka later described the 'deportation' of Jews from the Ghetto to nearby Ponary in the suburbs of Vilna, where the
Ponary massacre was carried out by Nazi Germans and their
Lithuanian collaborators. She wrote: Sarenka moved into hiding at the Polish Dominican Convent of the Little Sisters in a forest some outside of Vilna (see:
Anna Borkowska (Sister Bertranda), the
Polish Righteous Among the Nations who saved them). Reportedly, Sarenka stayed there together with
Abba Kovner and Joseph Shamir. In all, some fifteen to 20 comrades hid in the convent together. There, the idea of the uprising took shape, and became based around Kovner's declaration: "Let us not go like lambs to the slaughter!" The connection between the Hashomer Hatzair insurgents and the Catholic convent was arranged by Yodviga Dudezits with the assistance from
Irena Adamowicz, later acknowledged as the
Polish Righteous Among the Nations by
Yad Vashem. Both women belonged to the Polish Scouts Democratic Movement, and both had been hidden by Hashomer Hatzair activists when the city was destroyed by the Russians. After Moshe Kopito was murdered by the
Nazis while attempting to buy milk and supplies for their daughter, Sarenka placed Maya at an orphanage in Vilna, under the name Yodviga (Jadwiga) Sogak. Maya (whose whereabouts are not known) is still being sought to this day. At that time, the Hashomer Hatzair leadership in Vilna decided to return Sarenka to Warsaw for partisan action. Chaikeh (Chajka) Grossman was sent by the movement to bring Sarenka back to the capital. Sarenka dressed up as Chaikeh's child even though they both were young, but Chaikeh was the elder of the two. Chaikeh later wrote: "This time I didn't come to Warsaw alone. I came with Sarenka. I needed to get Sarenka from Vilna to Warsaw, after the catastrophe with Moshe Kopito, her friend. We decided to transfer her to a family in Warsaw and have her join the action there." The purpose of Sarenka's return was to continue leading the youth remaining inside the ghetto, and to assist her family with their grocery store inside the Warsaw Ghetto. ==Death in the Warsaw Ghetto==