In 1944 elections took place in the part of Greece that had escaped Nazi occupation and several women won election to a sort of "national council."
The first woman officially elected to parliament was in 1953 from Thessaloniki in a by-election. This may also have been the first time women voted in significant numbers. In the 1956 parliamentary elections, two women won seats, Two women were elected: Lina Tsaldari (ERE, right wing) and Vasso Thanasekou (Democratic Union, left wing).
Prior to the 1967 dictatorship there were never more than 4 women in parliament (out of 300 deputies). Women's participation didn't go over 10% consistently until 2000.
I wish I had better sources for this, and I am not 100% of the facts alleged here.
An analysis of women's voting patterns is "Women and Politics" by M. Pantelidou Maloutas, of the U. of Athens
A source for further information (recommended to me, but I have not read it) is Tasoula Vervenioti, "The Adventure of Women's Suffrage in Greece" in When the War was Over. Women, War and Peace in Europe, 1940-1956, edited by Claire Duchen and Irene Bandhauer-Schoffmann, Leicester University Press, 2000.