You know its her when:

- spending the rest of your life with that person makes your lips curl upwards, and not your eyebrows curl downwards
- the worst thing you quarrel about is why your fart is so smelly or your burp so loud
- the trust and understanding is so strong that you know what she is thinking about even before her
- when your sense of right and wrong tells you that it is the correct thing to do
- when it does not feel like 'being chained'
- when you throw your heart and soul towards making the eventuality a reality