My mother-in-law, born 1917, got a job with the Post Office Savings Bank* when she left school. I think this would be classed as a Civil Service job. She worked there for about 20 years. When she got married, late in life for the times, she had to leave. She got a job in the City for a while but left that too when pregnant with my husband. Many years later the Civil Service did a recruitment campaign aimed specifically at women like her who had worked there until marriage/children, to encourage them to come back. So she did, working part-time until she reached retirement age.
My Mum, born in 1932, also went into the Civil Service when she left school, but was able to leave after a short time to go to teacher training college. The baby boom after the war led to a huge shortage of teachers and a big recruitment drive. She couldn't have given up work without a grant and having the fees paid by the council or government, as her family had no money to support her. She was able to carry on working after she married, but gave up when pregnant with me. I'm not sure whether she was forced to or whether it was just obvious that there was no practical way for her to carry on once I arrived. We weren't living near any family and there were no day nurseries in small towns in Central Scotland at that time. I've no idea how easy it would have been to find a childminder and how much it would have cost.
I don't know for sure but I wouldn't be surprised if both MIL and Mum took advantage of something a lot of women did, namely to draw out their pension contributions when they left. Obviously money was going to be very tight once they weren't working, but this is one reason many older women have such poor pension provision - no entitlement left from their first few years of work.
Of course there was also the Married Women's NI rate, which was less than the standard rate because the assumption was that the married women could rely on their husbands to look after them so didn't need their full entitlement to the state pension and other benefits. Lots of women chose to pay that, again because money was tight, and regretted it later.
*National Savings and Investments now