My neighbor, who bought the property 8 years ago, claims that her underground pipes are invaded by roots of my Jacaranda tree. The distance between the tree and the fence line is 3.5m. She has already made other neighbors to chop their coral tree. Now she demands us to do this. As evidence she has photos of roots in the pipes and insists that they are roots from both tree. She is very determined to chop our tree. How can I defend my lovely tree. What is my responsibility?