Can my mother sell my deceased father’s house if it was only under his name?

In Florida, your mother could not sell a house that was in someone else's name.  However, the statute of descent and distribution for Florida and any other state provides who receives property if someone dies without a will (i.e., dies intestate).  Under Florida's statute, your mother receives all of your father's estate if your father and mother were still married at the time of your father's death and their only descendants are their children (i.e., neither your father nor your mother had children with anyone else).  It is, therefore, possible that your mother is entitled to all of your father's estate.  To sell the house, she would have to apply in the Probate Court to put the deed in her name.

If your father and mother were not married at the time of your father's death, then his estate would be distributed differently, and his children would inherit under Florida law and likely under the law of other states.

I suggest you call the realtor and ask who is selling the house.  That may clear up the mystery.  If it does not, you can call the Probate Court in the County where your father lived and find out if your mother opened an Estate to change the deed.  If so, you can view the file and find out what the Court did about the house.  If you think something is fishy about this, contact an Estate lawyer for consultation.

This situation shows at least one reason why everyone should have a will.  Preparing a will not only puts a person's wishes in writing, it causes that person and his loved ones to decide what should be done with assets and avoids upsets and disagreements.  Preparing a estate plan is an act of love and generosity toward the people we leave behind.