When an unmarried co-owner of a jointly held property dies intestate, her share typically devolves to her mother according to the Hindu Succession Act. The housing society's request for a release deed from other family members, such as stepsons or other daughters, may be misplaced if they are not the primary legal heirs. It's advisable to clarify the legal position with the society, potentially through a legal notice, to ensure the correct procedure for transferring the deceased's share to the surviving mother is followed.