1. Since the the title of your family house stood in the name of your mother who dies intestate, the said property will be equally owned by your father, yourself and your brother as per Hindu Succession Act.
2. As per Indian law, wife has no claim on her husband's self earned or inherited properties during his life time but can claim maintenance.
3. If you die intestate without getting a decree of divorce, she can claim your share of your mother's property since she stands as your sole legal heir as of now (without reported to have any children).
4. If your wife files any suit/case against your sister in law just for making a phone call from Australia, the said suit/case will have no legal leg to stand.
5. Has charge sheet been filed by the police in connection with the said FIR u/s498A filed by your wife. If yes, then your father can file a quash petition before the High Court picking out loopholes in the said FIR.
6. Ordinarily, no High Court entertains quash petition unless charge sheet is filed by the police against the FIR prayed to be quashed.