An ex parte decree is a decree which is passed in the non-appearance of the opposition. As per the principle of natural justice, any case must be decided with presence of both the parties and both the parties should be given proper opportunity to present them. However, in certain circumstances a court can pass an ex parte decree.
Though these orders are neither null nor void nor inoperative but are just voidable and unless and till the time they are annulled on legal and valid grounds, they are proper, lawful, enforceable and operative like a normal decree and have all the force of a valid decree.
Order 9 Rule 13 states that while setting aside ex-parte decree, the defendant may apply to the Court by which the decree was passed for an order to set it aside and if the Court is satisfied that the summons were not duly served, or that he was prevented by any sufficient means from appearing when the suit was called on for hearing, the Court may make such order setting aside the decree against him as it thinks fit, and shall appoint a day for proceeding with the suit, provided that the decree was of such a nature that it could not be set aside as against such defendant but it may be set aside as against all or any of the other defendants also.
Therefore, these are the only two grounds under which the court can set aside an ex parte decree. Also, as per Article. 123 of the Limitation Act, 1963 the limitaion period for challenging an ex parte decree is thirty days. Therefore her petition cannot be held maintainable.
Reference: Rule. 13, Order. 9, Code of Civil Procedure