1. She has to file a petition to condone delay in filing the set aside petition under section 5 of limitation act.
After this petition is allowed, she has to argue in the set aside petition.
In both the petitions you have to file your objections and strongly argue against the petitions she filed.
Please note that even if the exparte judgement is set aside, you can conduct the case properly and get a contested decree of divorce in your favour.
2. If she's got income to sustain her expenses then she will be eligible for monthly maintenance from you.
3. If you anticipate that she may do so, you may even file a petition seeking to restrain her from fleeing outside the country with the child without your consent to take the child abroad.
4. She doesn't have any rights in your property either before or after divorce.
5. You can ask her to get out and can decide about coming in if the divorce case is dismissed, until then, you can keep her out of the house, even by force, if necessary.