Divorce

My elder brother is a central government employee.He got married on 09.11.2011. Since then there has been no.of times she quarrelled with him and my parents. Later on 04.07.2014 they had a male child at nursing home near her parental house but due my sister-in-law's progressive ill health her parents insisted of coming back to our house. Then after a proper diagnosis for one month her condition improved and she was diagnosed with Systemic Lupus Erythomatosis. Then she slowly improved. But on February 2015 her parents insisted of taking her back to her parental house for few days. But then she never returned and refused to come back. Then my brother went to her place but she said she wants separation. Later that year parents went to her place three times september, october and december, but all efforts gone in vain. From January 2016, my father became ill and since then he is suffering from lungs cancer. Though we tried to communicate through message but they didn't responsed. Later my brother sent her two letters on February and April that time again we didn't receive any response. We also have reported the matter to our local police station andgot it registered in diary. Later we consulted a lawyer and he sent a letter on June 2016 to come back . But this time again they didn't respond. Now on 16.09.2016 , my brother filed a case for divorced. Later on 22.10.2016 I.e this month my brother received a letter from court regarding a new case registered by them for maintainance expenses. Now what shall we do. When he wanted her to come back, she didn't and now she wants maintenance expenses. What shall we do to avoid maintainace expenses.