1. If her husband is bale to prove her acts of cruelty, if she indeed did, then only he will get divorce. Getting divorce is not a matter of right or choice.
2. The divorce suit can be prolonged for at least 5-8 years.
3. The wife has no right of share in the property of her husband . However she has right of right of residence therein.
4. Registration of Will is not where compulsory in India and it can be done on white paper in simple language only.
5. She can cause searches in the local registration office , if the WILL is a registered one.
I do not think it was wise on your part to so easily leave your matrimonial home. Since you do not want divorce then put a brave front and file a case for domestic violence which is basically a case of civil nature.
In the said suit apart from claiming monthly maintenance from your husband, claim for right of residence as well.
if you were tortured by your husband and father in law then you can think of setting in motion the criminal case u/s 498A IPC as well.