My father has died last August. He has been re-married for less then 3 years.
What does the law say about...

Hoe long does a cupple have to be married to have the right to receive any pension funds?

Where? As long as a couple is married the spouse is entitled to inherit, whether it's 5 minutes or 50 years.

The reason I am informing about this is because some people say that they had to be married for a minimum of 5 years for her to be intitled to inherit. And what about (minor)children?

JudyKAyTee to your question where? In the state of Florida! And about the question regarding children... my father didn't have a last will...