How long does it take for a person to get American citizenship?

I have come back to my country to wait for my fiance. He is a uk citizen waiting for his american citizenship. But his mother is in America waiting for her citizenship too. We are waiting for his mother to get her American citzenship so that we can get Married because if we got married now my fiances visa back to america will fall away. His mother is busy with the process now and has gone for her first interview. How long will it still take for her to get her citizenship for America? As when she becomes a citizen we can get married and his Visa back to America wont fall away.

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia��).