Your goal here is not to change your in-laws, but to get them to alter their behavior as needed to protect your children and marriage as you see fit. This is your life, so you are the only responsible person to take right decision in right time. This is not a right time to ask your share from your family. Right communication with your wife and her parents are the only way to solve the problems. Talk to your wife openly and express your wish .Convey her about the problems for taking such decisions as ask the share from the family and want time for build a house.
In laws are more selfish or other wise they have some cause for thinking that.
If you see your in-laws as the enemy, you’ll never get anywhere with them. No matter how troublesome they seem, you need to take the lead in working toward solving the problems. One thing that might help is to remember that your mother or father-in law is different from your parents. You cannot compare the two, because in most cases your in-laws will come up short. Therefore, you need to get to know them for who they are, not for what you want them to be.
It is not desirable to cut off the relationship under the guise of leaving and cleaving. This is the hard time to face the real things happening ion life. So face with cool mind ,try to control what you do and what you say.Amicable settlement with the help of mediates is the best thing to solve the problems.
Don’t think about the consequences, if she files false case against you and your family. Face it in brave manner and defend with a good lawyer.Your primary human relationship now is with your spouse and children.If she is not join with you after the proper conversation or talking file a case for restitution of conjugal rights before family court.