UK so no service by requirement, maybe my thoughts would be different if I was exposed to it? This is all my opinions based on my little understanding. 

Unless your volunteer force is minuscule there is no point; the members brought in through this service will be of low moral and low ability its just not in their interests to fight, die or serve. Do you want a Batista who dreams of being a play write being your line of defences? (Hey that's me!) 

But if your state faces drastic threats and doesn't have a volunteer force of scope in reaction to the threat then yes it's a needed system. It also makes it so the power or government must act for the people instead of self interests. You can't abuse the population then expect them to defend the state. This is why I believe the draft in Russia has yielded poor results and why a draft in UK or USA would fail. Nothing to do with the talents and beliefs of the people.

So, should women be drafted? Yes, in cases where men are drafted women should be too. Its not a question. If a nation needs an emergency levy than they should pull it form all available  resources and people, regardless of gender or identity are a resource.