My mom's estate, No will established

[Meleneal Cameron]

First of all forgive me if my legalese is not on point.... My mom bought a home back in the early 1990s, afterwards got married and her husband moved in with her.  She never felt comfortable putting his name on the deed of the home.  However, she recorded all 3 of her children as beneficiaries. She passed in early 2014 and my step dad stayed in the home and remarried within a year. He asked if we would be willing to sign legal administration papers drawn up by his attorney where we would him rights to the property. From there, he wanted to write his new wife into this agreement so that if something happened to him she would get the property.  I flat out said "no, perhaps your new wife can share your retirement, pensions, etc, but not the equity in my mom's house."  At the time my mom passed she owed only $14,000 on the house.  I just recently found out my stepdad has paid the loan off.  The home is in great condition and in a great community.  We are not upset with my stepdad, plus he's now in his mid 80's - we thought it would be wrong to attempt to force him to move this late in his life.  My concern is how can we protect my mom's investment and her original intention to pass on her wealth to her children? She never created a will, she only recorded us as beneficiaries.  Thanks in advance for your advice