FiL's family were all farmers so were well fed and had their dads around (none seemed to fight)
Yes farming was a reserved occupation, as food supply was a critical national issue. But farmers - as the pool of able bodied young men - were trained secretly as SOE operatives in case of invasion - something that was only made public comparatively recently
Britain’s secret resistance plans | The Past (the-past.com)
Supply of doctors was also considered a critical national interest, and everyone's career was taken over by the ministry - most young men were sent directly to the forces, but some were ordered to stay (know someone whose father was sent to London and worked in a hospital there in the Blitz) because it was important to national morale that there was proper treatment of casualties here and as good a service for everyone else as possible (GPs were largely those to old to be deployed to war, some back out of retirement, women, or those with injuries or a medical condition that ruled out military service)
Medicine supply by and large held up, but there could be interruptions, and so there was a great deal of stoicism and people tended to seek treatment only when they were really not coping
Women were not conscripted, but men were. So nearly all teachers were women (only the men unfit for other war occupations remained in schools). As the schooling of children was held to be in the national interest, so women teachers were not sent off to war industries, land work or nursing.