What's this? Truly, you ARE a new player if you haven't heard of the hallowed tradition of the fearless dwarven shieldmothers and their short-lived babyshields! (Many players have a "no married women in the military" or even full gender bias "no women in the military" policy to avoid this... others see babyshields as a benefit, as children are rarely of benefit to a fortress that isn't going for generation fort status, and dwarves are quite fecund, anyway.)
In all seriousness, though, I don't think this is the sort of thing that needs suggesting, because Toady's already well aware of it, it's definitely not the sort of behavior Toady intends out of dwarven mothers, and there are bug reports galore about issues like the training weapons thing as well.
For the time being, just make sure to micromanage your dwarves and make sure that they have their proper uniforms before letting them out into battle. (Using doors and locking them strategically in the face of a dwarf about to head into battle with the wrong equipment is a good way to stop dwarves from doing something stupid. It's also a good way to help make sure the dwarves all arrive on the battlefield at once, rather than trickling out to get slaughtered one at a time. For that matter, try to rely upon traps first and actually send in your dwarves to fight as a last resort when you're new - you have control over the terrain of the battlefield, so take the greatest advantage of that as you can.) The uniform menu allows you to be extremely precise about which weapon goes to which dwarf for a reason.