Regarding issue with regards to ownership of property

Who would be the proper owner in the following case: A) Mrs. Sharma bought a property from the only son of the owner (Owner ie. father died long back) in bihar who has three sisters, all of them married. Mrs. Sharma has the full documents required to prove her ownership. B) But 4 months before the property was sold to Mrs Sharma, the same property was sold to another women by one of the sisters of the owner. Here, an individual disguised himself to be her brother and participated in the proceeds of the property. Now even she has the papers to be shown. Now, the bone of contention is that who is the legal owner or should be the legal owner of the property: 1) Should it be Mrs Sharma who purchased the property from the legal heir here in Bihar? OR 2) Will it be the other lady who so called bought it from the sister of the owner here in bihar? What should be the further procedure or steps to be followed? Requesting the esteemed advocates here on this platform to kindly guide me and suggest me the best possible way ahead.