Thanks for your question. It's a very difficult situaiton and I do sympathise.
Basically you're going to need to instruct a solicitor to act on your behalf (and those of your siblings).
Under the intestacy rules, his current wife would receive all his personal possession and up to £250k of his estate. Anything over this amount would would be split in half with one half going to his children and the other half being held in trust for the children but with his wife receiving the income from that amount until she dies.
It's going to be quite difficult to enforce the verbal representations that he has made that the house should go to his daughters.
You and the children who have not been provided for may be able to make a claim under Inheritance (Provision for Family and Dependent) Act 1976. You must make the application within 6 months of the date of the grant of probate in the estate and you will need a solicitor to do it for you.
The Court will consider what is a "reasonable financial provision" for you and will take a number of factors in to account in determining what is fair (eg. size of the estate, other claims, resources and needs of other family members/dependants, responsibilities the deceased had to you), each case turns on it's own facts and there are no hard and fast rules to work out what you are entitled to.
In all likelihood you will enter in to negotiation with the step mother over what should happen to the house, or the proceeds of sale of the property if you agree that it should be sold.
I would use the following Law Society search engine to search for probate solicitors in your area, call round a few and ask if they practise "contentious probate". Most will and you should go with your siblings for an initial free of charge (of fixed fee) meeting to discuss your case.:-
Sorry it could not be better news, I wish you the best of luck.
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