Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
Do you know if you hold the property as Tenants in Common or as beneficial joint tenants?
The best way forward would be to change the ownership to Tenant sin Common - so that you each own half of the property.
You will then be able to preserve your mother's half of the property and share it with your siblings when and if the time comes no matter what your father has chosen to do with his share
Please ask if you need further details