You don't say what country you are from. We can only guess that you are a foreigner as most of us are. The family rights system here is different from what most of us are used to and as foreigners we have no say in anything anyway, so to me it looks like it boils down to a family matter concerning the siblings to work it out. Tukaram may have some thoughts on it as I think he & his Asawa built a house on family owned land. You might do some searching on 'Family Law in he Philippines'