False domestic violence and dowry

my brother who is in merchant navy got married to a middle class girl,2.5yrs back...he is earning very well and the girl in her initial 1st yr could not go on ship with my brother as she could not get visa...2nd yr when she got visa my father got heart stroke and this yr covid so she could not go on ship for these reasons till date...she is working though as brother is when on ship she kills her time while working in finance and accounts snd is a CS too...in her 1st yr of marriage she was also caught sharing love affair messages with a guy to which she apologised later and started leading her luxurious life being a wife of merchant navy officer...at the time of marriage girl's family gave the guy rs 5lakh as a gift and when they gave this amount before marriage and after engagement and asked my mother we can take car or cash to which my mother said cash the couple will spend give them car of your budget and they recorded this conversation..now it seems this relation was started with conspiracy only...now this yr when my brother had gone for his job on ship in march and came back in sept due to lockdown...the girl was staying very nicely with my brother and suddenly one day she goes to office and from there she goes to her mothers place without informing anyone...when my brother tried to call her she doesn't ans ,we called her,her family but no body answered for hrs then in the evening girls calls my brother and when he asked where are you and shouted on her that we have been calling you since morning and whete r you..she says that i am at my mothets place and why are you shouting at me and so on and i don't want to come now...then the next day their relatives called and says that the girl now will not come back lets sit mutually and close it...we were in shock and thinking what to do,the next day we got a call from police thana and when we went there we were told that the girl wants divorce and 35 lacs...she allegated for domestic violence and dowry for which they gave us 5lac...she has the recording which is edited too... now what shall we do...do you think when the boy is earning 9lac rs was greedy for 5lacs...that money has been spent by both of them in an international trip already...as girls mother said that you can go somewhere with this gift amt... our women cell part is completed too...now we came to know that the girl is involved somewhere and wants money as her financial state is not good at mother's place...they are approaching us to go for mutual and give them 35lacs.. do you think the audio they have is of any good... this girls plan was to marry for money only with a merchant navy officer..