As far as I know, the deed is just a regular deed but all this is excellent information to be aware of. We did see a lawyer at the time but no one mentioned anything about my moms estate and what we should do. We only were there to get durable power of attorney and to protect my father
We paid any creditors that were owed immediately so that is a non issue.
At issue is a pending wedding to a woman much younger than my father and she has a history of taking inheritance that should belong to others.
If the deed was just a usual husband and wife deed in both your parent's names, then when she died it passed to your father 100%. It is his to do as he wishes. The impending marriage will affect this situation. Hire a lawyer but your father is the one that is in control. Best of luck