I want to create a beautiful nord warrior or elf queen but i just can't see myself playing a female..is that sixist or common?
I think that some people may not understand the meaning of being sixist or the idea of sixism. However, beyond that, both physical six and psychological gender are continuous spectrums, not dichotomous categories. For example, there are many intersixed and transgendered people. Concepts such as "masculine" and "feminine" are social constructions. Your personal concept may not be the same as other peoples' concepts.
As for a female/feminine character being Dovahkin and whether or not female/feminine characters are realistic in medieval combat settings, Skyrim and the Nord race in TES is inspired by Norse mythology and Scandanavian cultures. Goddesses in Norse mythology are extremely powerful (e.g., Freya, Sif, the Valkyries, etc.) They are also extremely feminine and extremely beautiful. I am not sure why anyone would not be intimidated by such a female/feminine character.
Part of the fun of playing tiny, fairy-like nature spirits is that enemies are misled by their perception that such characters are harmless and easy prey. There are many things in nature that seem harmless but are quite deadly.
Finally, strengths and weaknesses vary between individual people but have little to do with someone's physical sixual identity. You can see this in fantasy works such as Lord of the Rings (dwarves move slowly and use heavy armor and heavy weapons but elves move very swiftly and use lighter armor and weapons, but both are deadly regardless of any individual's physical sixual identity). On average, women have higher tolerance for pain, higher levels of stamina and endurance, and higher tolerance for cold. Also, the leg muscles are the strongest muscles on female bodies.
You also have a great diversity in masculine forms. This is brought up in movies such as U-571. Most of the American sailors are too big to fit into the bilge compartments to stop the leak and activate the rear torpedo. Only two of them are small enough to do so, and might be called "more feminine" compared to the other male sailors. One of them is ordered to go into the bilge and winds up drowning, but manages to plug the leak and thus save the lives of the rest.
Another example of this is during WWII where the Japanese Zeros were stripped of armor and the Japanese pilots tended to be smaller in build than their American counterparts. On average, there was no way for American fighter planes to outfly the Japanese Zeros. The Zeros were far more manueverable, but they could not take any hits.
There is some kind of mistaken idea that "bigger is better" or at least "bigger is stronger" but that isn't true.