My sister's husband left her after marriage after getting dowry.

Hello Sir/Mam, My sister got married in April 2015 after 3 months of marriage her husband stopped talking to her and also his family started mentally harassing my sister . Her mother in law started abusing her and keep torturing her for every done. They keep saying one thing to her always you're not active, your father made us fool and left on us and so many things. On Rakhi her father in law asked us to take her from their house and send her back when she become capable and get job, since then she is staying with us. Its been 2 and half months her husband haven't talked to her for once . And now they're(his family) saying that they aren't happy with this marriage and want divorce. I want to mention we did best whatever we could in marriage. As they asked for dowry we have paid Rs. 8-10 lakhs cash to them and also around Rs. 8-10 lakhs gold jewellery other than furniture and basic items. They digested it all. I am seeking for advice as she is B.com graduate only and not having any job so would she get alimony for herself and also all the dowry we paid to them including gold ?