Since your father is absolute owner of the house your father should file suit and seek court orders to direct daughter in law to vacate portion of house in her possession
2) seek injunction restraining her from disturbing his permanent possession of the house
3) daughter in law has no rights to stay in house standing in name of father in law
4) you should file application for discharge before trial court under section 239 of cr pc after charge sheet has been filed
5) If the trial court does not discharge the accused, it may then be challenged before the High Court under Section 482 Cr.P.C. in appropriate cases wherever it is permissible.