Grandma's spouse died, she's on deed, spouse's kids living in it

[Ryan Jones]

Location:  Houston

Situation:  Husband and wife were on property's deed as they were married and bought it together 15+ years ago.  However, she moved out over a decade ago.  They were always still legally married.  The husband had a previous marriage with children and one of them was living with him while he was alive.  After he died, that child (about 45 years old) now still resides in the home.

Question:  Can the wife (grandma) simply sell the house (value approx $150k) since she is on the deed?  He left no will.  (I'm assuming most state laws say that a property simply remains to the one left on the deed).  The female child claims it is half hers since he had no will and she's been living in the homestead.  Would the wife have to get an eviction going?  I believe the home is fully paid off; apparently the child has been paying the property tax semi-annually but apparently has been living rent-free.  The wife (grandma) is a bit of a pushover...I'm trying to get her to sell it now so she can at least have that money invested and working for her.  Plus, if grandma dies, it would leave the headache for her daughter to figure out.  I'm trying to help...advice appreciated!