My name is Clare
I shall do my best to help you but I need some further information first.
On what ground does your half sister think that she can oppose the Will?
not sure if my reply reached you. I do not believe she is has any grounds to contest the will. my question is, if she did and was successful, would she get a third or nothing under intestate rules.
Sorry for the delay.
If the Will was indeed found to be void then assuming that she is not your father's biological or adopted daughter then she would inherit nothing at all
I hope that this is what you wished to know
thank you.... this clarifies matters for me