"and the European War which opened the doors to the average woman"

The 'European War' referred to by Virginia Woolf is now more commonly known as The First World War or The Great War (1914-1918).

Whilst men were at the front, women took over many jobs which had previously been male preserves.

Government poster (1917) to encourage women to join the Land Army
Public DomainGovernment poster (1917) to encourage women to join the Land Army - Credit: Henry George Gawthorn (1879-1941)