My father did a settlement to me

My father did a settlement (His fathers property) to me and after 3 months there was case filed that he had a illegal wife/child and she need share in the property. 1) After 2 years of this case my father died. 2) My fathers sister is alive and dont have contact with our family because of property problems. But she is supporting illegal child and ready to appear in court to say that she is the child of my father. 3) Now she dont have any supporting document to prove apart from school TC which has my father name without initial mentioned. My question here is, 1)Since we are "not" in good terms with my fathers sister. She will be opposite to us - Will her witness valid ? Consider if its valid - will it break my settlement ? 2) Also my father don't have any property in his name when he dies. All he gave via settlement to me before the case was filed. Can the rule break my settlement ? ( Currently I am taking the possession of the property and all EB/Water/Tax are in My name )