I am currently assisting two clients with estate administration for their husbands, both of whom died very suddenly and without wills. The situations are opposite, and it comes down to a separation agreement.
For my first client, she and her husband had been separated for a long time, but had not signed a formal separation agreement. As a result, when he died, she was able to take over the estate, and she will receive a full share of the estate.
For my second client, they had signed a separation agreement two months before his death. Because of this, she will not receive any of the estate, and is limited to offering advice and assistance to her son who will be acting as the executor.
Separation and divorce can be a very painful time, and a very stressful time. Having a will in place ensures that the person you want to act, will be the person who will actually act.