My husband’s will give away all our joint property to his son.
You can reject (renounce) the property given to you in his will and receive what you would have received as if he died without a Will but not more than 1/2 of such amount you would have received. What percentage you receive depends on number of children. If one child, you receive 1/2. There are also other laws that provide for the support of the spouse that could apply.
