evil stepchildren

What is the name of your state? Georgia
my mother and stepfather built a home above a row of apartments that he already had. his children have convinced him to leave everything to them with the stipulation that they will allow her to continue to live in the house and collect monies made from the apartments. isn't she entitled to half of his assets anyway? and shouldn't the agreement about her living in the house be stated in the will? she is afraid to "rock the boat" for fear that they will throw her out of the house after he dies.

I do not know what her state law provides in terms of what happens without a Will. Or what she can do in terms of an elective share if there is a will -- what she can take regardless of the Will. BUT in many states by placing property in joint name (father and kids, for example) he can effectively reduce what she can elect against, and pass the property to the kids without probate, as the Will does not impact jointly held property.

She should get her rights spelled out, ideally in a Will. A "life estate" in the property seems reasonable.