Firstly, it is advisable for you to consult some local lawyer and show him the detailed papers and facts, in view of the complicated fact situation and also in view of the question as to which particular law applies to succession to property of your father-in-law. Moreover, you have not made it clear when did your father-in-law expire.
Presuming that your father-in-law died after 2005, and that he is governed by Mitakshara law (which is generally the case), your question should become an academic question, in my view. This is because an amendment to Section 6 of the Hindu Succession Act lays down that where a Hindu dies after the commencement of the Hindu Succession (Amendment) Act, 2005, his interest in the property of a Joint Hindu Family governed by the Mitakshara law, shall devolve by testamentary or intestate succession, as the case may be, under the Hindu Succession Act and not by survisorship, and the coparcenary property shall be deemed to have been divided as if a partition had taken place and also that the daughter is allotted the same share as is allotted to a son.
Even otherwise, from the facts mentioned by you, it appears that the property of your father-in-law would be divided in accordance with Section 8 of the Hindu Succession Act, as per which daughter will get equal share.
However, as mentioned above, what I have mentioned is on the basis of incomplete facts. You should consult some local lawyer and show him the relevant documents / facts for a proper advice.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.