There are a couple of reasons young boys were conscripted over women.

First off, Germany, much like the other Axis nations have a deep culture rooted in warfare. Prussian military traditions were embedded into the German mind and this is especially true during Nazi Germany with national socialism. In Prussian culture, it’s the men and boys who do the fighting and wage war. It’s inappropriate for women to be put into that position, and for various reasons. Another reason is because that same culture at the time held the belief that women can best support the war by taking care of their families and having children.

But perhaps the largest reason is that of the US, UK and other nations of WW2. From 1941 onward, Germany had problems with manpower and men working in factories. Generally what would happen is between campaigns the German soldiers would work in factories and then go to war, once that campaign ended they’d go back to the factories. This was what it was like for Poland, Norway/France and a couple others. Now Germany invaded the USSR in 1941 and German commanders told the factories that they’d have their manpower back in 3-4 months after Russia was conquered. Well Russia was not conquered in that time. So now Germany has a large amount of its manpower fighting in the war so there is a need to fill factories with people. This is where women come in and did a lot of the factory work. Because of the cultural traditions at the time, it became the ideal place for a women, was the factory.

But make no mistake, German women did on some occasions fight. Such as when the Soviet and western allied armies came into Germany in 1945, and found themselves in situations where they were forced into a frontline situation. But these were far and in between and generally didn’t happen as often as one may think.

I hope that answers your question, let me know if you have any follow up questions.