Over one-half of Americans do not have a Will. It's self-evident that having a Will or some other form of organized estate planning is crucial to saving your loved ones headaches and expenses like the one you're going through with your family. With the "paradigm" family of old giving way to a wide variety of family relationships today, its even more important to get your estate in order.
In your situation, I'm assuming that your parents' names were the only names on the deed. If that is the case, when your father passed away, the property was owned solely by your mother. Since she passed away without a Will the property would pass to her children (natural or adopted) only. Step children would not inherit the property. In order for the deed to be retitled or sold, it would be necessary to open a probate proceeding in the county where your mother resided at the time of her death and possibly in the county in which the property is located.
That may not have been how Mom and Dad intended it but those are the unfortunate consequences of allowing your estate to pass via the laws of intestate succession.
Answered on Nov 14th, 2014 at 2:52 PM