You call that a long rant? That's barely a drop in the bucket compared to some of my long rants. Anyways, I can certainly understand designing weapons. I'm not much of an engineer, but I've thought up a design for a wrist-blade/wrist-gun combination; if I could get the design of the magazine, the firing mechanism, and the extend-retract mechanism down, it could essentially be a compact, concealable (as long as you wear long sleeves) assault weapon with excellent accuracy, at least compared to other assault weapons. Anyways, with a shield like that, if you used several thin layers of quality steel or perhaps titanium and then sandwiched in some foam rubber or something similar, it would be strong, lightweight, and would absorb impacts fairly well. The additional steel plating would conceal the bladed edge of the shield until it's too late and, if you polished it to a mirror shine, you could easily blind an opponent by reflecting light directly into their eyes. If you were quick enough with the xiphoid (wrist-blade), it'd be a "hissatsu" (sure kill).

Also, while it's a good idea to consider the character's strength, wood is actually fairly dense and gets heavy pretty quick. For example, a wooden Hoplite shield (think Spartans from the movie 300 for size) weighs about 22lbs while a steel version weighs only 8lbs. You'd also want to consider the harnessing system (how she holds it); is she just holding it with a single handle, is it strapped to her forearm with a single strap while she holds a handle, or is it strapped to her forearm with two straps, leaving her wrist free? Personally, I'd prefer the third approach, as it allows you to wield a second weapon (a bow, perhaps) if necessary without removing the shield, though a handle to grasp would be important for better control during strikes, so perhaps a combination of the second and third methods?

Hmm... It would allow her to still crouch down and thrust the shield into the ground (best to have a thick spine on the "blade" like a Greek spear to avoid damaging the tip) to weather beat down tactics from a stronger opponent, while give her extra strength in various attacks with it, and it would be near impossible to rip it off without taking the arm with it. In addition, instead of taking blows full on and denting the steel, she could angle her arm in combat slightly and use the steel's natural hardness; after all, if you hit steel with steel, it skates off (not a deadlock like in the movies), whereas if you hit wood with steel, the blade will either bounce off (good) or sink in (good or bad, depending on the strength of the opponent and the opponent's grip strength). A curved surface would be ideal for the shield, which is easier to achieve with steel than wood (with wood, it has to either be cut that way or steam pressed, which is modern technology, whereas steel just has to be beaten into shape).

Finally, the main problem to consider with wood is that it rots (steel rusts, but rust is easy enough to prevent) and if it gets wet, it warps, which would place terrible strain on its steel bolsters. Plus, if the steel ever gets damaged to the point that it's unusable, it can be melted down and reforged good as new. Of course, this is mostly theory as I prefer swords and this principle applies to them, but it should still work with something like this since it's all steel. On the other hand, wood is easier to come by in most places, so even if it were to rot and warp, you'd only need to save the steel fixtures and you could pretty much use the rest as firewood once it became unusable and then just make a new one, though frankly, having to cut it to shape each time would be a demanding job for anyone (unless you employed a Viking style of shield making, where it's essentially just a couple of planks lashed together with a steel border) and would waste a lot of wood, so the steel method would probably be most preferable, since skilled smiths are easier to come by then skilled armorers/shield-makers/woodworkers (I'm not really sure who you'd go to with such a project).

Anyways, it's my turn to apologize for the long rant. I think "practical" and start applying every bit of real world physics I can come up with. That aside, it's really an excellent design, so don't mind me; I'm just being nitpicky to see if such a design could be perfected for real world applications, even though the only shields used any more are used by SWAT (and similar organizations around the world) and riot police. And those are only meant for defense and are usually clear and unwieldy, only meant for marching in formation. Plus, most bullets these days would be easily capable of piercing either design, so thinking in terms of pitting it against bladed weapons is fairly useless except when considering it for a novel or game.

--
Optimum est pati quod emendare non possis.

A Bus Station is where buses stop. A Train Station is where trains stop. On my desk, there is a Work Station.