I totally agree with Ambika ji"s views.
Now, if we are conversing in English, we have to follow the way how a man and a woman is addressed in English speaking Countries, obviously.
The term "Sir" started to be used in UK military for males and its female equivalant is "Dame" there. In Indian military "Sir" and "Madam" are used as it is so in US and other English speaking countries.
It is now in common use to address a male as "Sir" and a female as "Madam" as a social norm including almost every country. So, in my opinion, to address a female as "Sir" would be a serious faux pas.