I do a lot of historical RPing and in those I tend to prefer sticking to the confines of the period. For example, you won't find a woman on the battlefield during the American Civil War, unless she had a very convincing disguise(even then if she got caught there would be trouble). I'm not a huge accuracy Nazi when it comes to facts in a historical RP, but there's some important conventions that just can't really be broken and gender roles is one. In fantasy RPs I'm much more flexible. If you want to have a badass female knight then go for it, haha xD.