When Nigel died, I found that I was entitled to a benefit called Widowed Parent's Allowance (thanks JanH for pointing that out). This benefit is paid to wives/husbands to support children under school leaving age. It has been crucial for me, and I know there are plenty of peopl in a situation like mine who are not even aware they are entitled to claim it.
The government very cleverly decided to tax this, which is just plain ridiculous. There is now a petition against this, so PLEASE SIGN IT to try and end this money grabbing exercise by the government.
Link to the petition. Please click and sign.