There wasn't really any such thing as 'female armour'. Theoretically it'll just squish your squishy bits like a corset would. In a design like that where it's just got basic shoulder straps you could just make the top panel a little more generous if you are particularly chesty.
Also if it's for costume I wouldn't bother hardening it (which is what the baking is for, though IMO it's not the best way to harden) ... I'm not sure how 9oz translates to what we use (over here leather is listed by thickness in mm) but something like 3.4mm leather holds shape just fine and can be easily water shaped if necessary... For that piece you wouldn't need to do much shaping, the only thing you'd need to wet it for is any carving you might do. You can see in that image most of the details is stamped or carved, there's not a lot of '3d' to it, mostly lines and panels.
You don't need wax to harden leather at all. You can simply expose it to hot water, it's a bit of an art. http://www.arador.com/construction/waterleather.html