Vealmoor, TX Estate Planning Law Firms & Lawyers

While a surviving spouse has a lifetime right to occupy the house in Texas, once he leaves, that right is forfeited.  From your reference to "half" it appears that the house was community property and you are your mother's only heir.  Your stepmother may be your father's heir but only after he dies.  She has no rights while he is alive.  You may try to persuade your stepfather to join you in selling the house.  You may offer to buy him out or have him buy you out.  Given the time that has passed, you may sue for partition, forcing a sale.  Contact a local probate attorney.

Your duties are set forth in the Michigan Estates and Protected Individuals Code (EPIC). You should hire an attorney to provide advice and guidance as you go forward.

In Texas a surviving spouse has a lifetime right of occupancy in the home.   Your father's Will may or may not say that he contracted with your mother not to revoke the Will in order to provide for her and for children of their marriage.  If it does not, he could Will the home to his new spouse.  You are correct that she could give up her right to a community property interest in the home in a valid prenup (or a valid Marital Property Agreement).  She would still have a lifetime right of occupancy and, if she paid on the mortgage or made other financial contributions, a right to be reimbursed for them.