Joint property ownership means both have equal rights on that property. But since you're paying EMI's, you can take legal help to get rights over there.
If your father-in-law has purchased any property from his own income / loan, it's his will where to pass that property after his death. He needs to write Will for that. But if it is inherited property from his father / grand-father, your husband and your daughter have also right in that property irrespective of his Will.
In anyway, I suggest you to take legal steps to get divorce, monthly compensation, property rights etc. Get all the documents ready. If possible, try to collect paers of your husband's assets like bank account, PPF, Gold, stocks, mutual funds, property, insurance policy, credit card statement etc.
Hope it will help you.