1. If you have personally spoke to your wife and her family and tried to bring her back, get a legal help to send a legal notice asking your wife to come and stay with you. If she refuses to join you despite the notice, file RCR -petition of Restitution of Conjugal Rights, in the court . Engage an advocate to send notice.
2. When you send a legal notice, take care that you are trying to save your marriage and bring your wife and child, and not making a base for a divorce. So the advocate who send the notice should be instructed accordingly. If possible request your advocate to talk to her family and try to bring them, for a talk.
3. You should try whether your family friends or relatives who can be a neutral mediators can help you to talk to them.
4. Do not be afraid there are many ways to tackle this issue , so approach it wisely and ready to forgive if she troubled you and your mother because she is now your child's mother.
5. Legal complications and technicalities which you should anticipate is , that she can file a 498A complaint following FIR- most likely if you do not have a history of events where your wife was physically assaulted or dowry was asked or demanded , then you do not have to worry about it, in case she files a police complaint move to the nearest district court and file for anticipatory bail.You will get bail as these days 498A is used as a weapon and the Supreme court has made many observations about the false 498A cases and you can surely rely on it .
your wife can file domestic violence mainly asking for a separate accommodation and maintenance for herself and child , which court will give you time to reply and defend. If her articles or sthreedhan with you , she can ask for that. Sthreedhan means what she brought from her family and what she earned by herself after or before marriage exclusive of the gift you have given her.
The last legal step from her part can be divorce , where you will get enough time and chance to prove your stand and defend. So do not worry hire an advocate and do the needful or get your friends and family to mediate and bring her back.