Shamna is a relatively tall woman with long blonde hair and blue eyes. She has a fairly average yet curvy body and has a Geass sigil on her pelvis.

Shamna is displayed as a self-centered woman who only cares about her power and holding her position above her subjects, it can be seen that she does deeply care for her brother. However, she also seems to use her brother as a method of displaying her "prophecies" to the people of her kingdom. However, her ultimate motivation is to save her struggling homeland that is upon hard times due to the peace created by the Zero Requiem and the betterment of her brother Shalio.

She holds herself above her guards and seemingly doesn't care whether they live or die. Whether or not this is just due to her Geass changing her perception of life and death is yet to be seen.

(Source: Code Geass Wiki)