My female Klyros character, Rhicora, has been called "sir" one too many times! PLEASE check the description of any Klyros you run into before using terms such as "sir". This is especially true if you are playing a Klyros yourself, who would certainly know any difference that exists between a male and female Klyros!
On a related note, Kran are not male or female, so you shouldn't refer to them as such. It can be hard to do so, but it'll be more accurate.