Yorkiegirl, it is very generous of you to think of posting about this. It is something that I have thought of often after the sudden death of a friend's husband.
The thing is, even though they had been together for 15 years, they were only married for a year or just under. We live in the US, and he had been in the military. If they had been married just a bit longer, she would have been entitled to his military pension benefits as well as healthcare (a huge thing over here, as you all probably know). Also, he did not leave a will and had five children by a previous marriage. She has now lost her home, everything they had money-wise is in turmoil as she is only entitled to a child's portion of the estate - i.e. a sixth. It is a horrible, horrible situation. If they had only married a few years earlier, most of this would not be happening. With marriage and a will, none of it would be happening.