I make decent money ($70K per year) and I have two properties right now, my primary residence and a rental property.

We have an "accidental" rental house in rural Missouri that was originally bought as a primary residence and taught us all about what doesn't make a rental house profitable, so that is the extent of our experience so far. 

In the absence of formal or informal lease terms (and considering the lack of rent), the sons are probably not tenants and thus eviction may be an inappropriate solution. 

If not covered explicitly in her will, it will likely be addressed in probate (depending on the laws in her state or residence).

However, they are unlikely to lose the primary residence.  

@Aaron Maxwell Is this a primary residence or an investment property?

if the residence is not usable for residential purpose doesn't the tenant have to vacate the premises if they are claiming this until the situation is remedyI see you are from Montgomery County Texas.  

I have only flipped my principal residence once , what ill do is out a suite in and make it a rental.

I just learned however, that because I have cripple walls taller than 4 ft. my house requires an "engineered solution that meets Chapter A3" to qualify for the grant money.

For example, home purchasers often include a contingency that specifies that the contract is not binding until the purchaser obtains a satisfactory home inspection report from a qualified home inspector.contractAn oral or written agreement to do or not to do a certain thing.conventional mortgageRefers to home loans other than government loans (VA and FHA).convertible ARMAn adjustable-rate mortgage that allows the borrower to change the ARM to a fixed-rate mortgage within a specific time.cooperative (co-op)A type of multiple ownership in which the residents of a multiunit housing complex own shares in the cooperative corporation that owns the property, giving each resident the right to occupy a specific apartment or unit.cost of funds index (COFI)One of the indexes that is used to determine interest rate changes for certain adjustable-rate mortgages.