Interestingly, Britain was the only country in WWII to conscript single women. Even pregnant women were liable for conscription though in practice this didn’t happen.

National Service, which had begun in 1939, didn't actually finish until 1960. During the war this was known, fairly understandably, as War Service (which is how it appears on official documentation for things like Pensions and National Insurance) and after the war as National Service.

The National Service Act of 1948 formalized the rules of conscription wherein all men between 17 and 21 was expected to serve in the Armed Forces for 18 months and then remain on the reserve list for a period of four years.

All women were released from National Service at the end of the war.