Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
Was the money given as a loan or a gift - and what other assets are there?
I am sorry for your loss.
What financial provision is there for her son?
Unfortunately it is likely that the property was held by them as Beneficial Joint Tenants and the property there for passed to the husbands sole ownership outside of any Will or intestacy
I am afraid that the step father has no liability to maintain her son.
Sadly since the money was a gift and not a loan the Grand parents cannot recover the money that they gave.
I am so sorry to give bad news, please ask if you need further details