Property layout has changed from the will, property under construction with another agreement

A will was made prior to signing an agreement with a builder for construction of the house which has altered the current layout of property. Will divided the property in the following way - Basement - X (Daughter) Ground Floor - Y (Child of Son - Grandchild) First Floor - X (Daughter) Second Floor - Y (Child of Son - Grandchild) Rights to construct other floors on top of it - Y (Child of Son - Grandchild) Now the will is 5 years older to death. 6 months prior to death, an agreement is signed with builder to construct the house. Builder gets one floor + XX amount of cash. This new building doesn't have a basement in the agreement signed by the original property owner. Now he passes away after few months of construction getting started. All payments from Day 1 (and the whole cost was borne) to the builder have been made by the Son who hasn't a got a share in property according to the will, though his son has. Questions - If the daughter refuses to sign the papers to give away her right (settlement amount being asked is high and she hasn't shared she knows about the will though we highly doubt she knows) and this matter was to go be taken up legally in a court of law - -What would be the distribution/shared proposed? -What do you think the distribution/share of daughter be? -Can the daughter obtain a stay order to prevent possession of the son & grandchild since the property is under construction and they are living somewhere else. -What would the ideal thing be to do here? Please note : No direct conversation around the existence of this will has taken place in any of the discussions.