18 of HAMA

When you allege any thing in an indecent manner that itself will bite against you. You better contact a competent lawyer who deals with family law. Best of luck

you can put all the defence in your reply viz.  behaviour of sister and your innocence.  its easier to level allegations but difficult to prove them.

If your wife has put forward all such allegations .... then she will have to prove the same .... mere allegations do not suffice .... she has to prove everything by leading cogent evidence before the court ...... It is obvious that u have to deny all these and state your stand in ur written statement/defence ..... and prove ur sayings by leading cogent evidence before the court ...... there would be admissions, contradictions and omissions etc in the evidence lead by both of u which will help either party to prove their respective stands ..... further alimony/maintenance will be granted as per the ernings, status and lifestyle of the parties and claiming exorbitant amount as alimony will not help her.

Yes - you can also highlight about your wife's sister's similar behaviour in your reply. Onus of proof lies on your wife to prove all the allegations. However, if both parties' relationship is irreconcilable and irretrievable, heading to marriage break-up, maintenance/alimony will become inevitable to be paid by you, if claimed by your wife.