thank you for rating on previous Answer. i think you child is smart and also to there no law to benefit you alone they have there rightful share and they can claim same through court vide partition suit.
Yes sister will have share and further for L share his daughter and wife will be entitled.
See in both the properties mother share (50 percent) after her death will be divided between her legal heirs that is you all siblings you your sister and since the brother is demised then his share goes to his legal heirs (wife and children) and your father if alive.
Further in one property you are sole owner of half share and in the other property since after demise of brother his 50 percent share shall go to his wife and daughters.
Yes your sister shall have equal share in the share of mother. This is law section 15 Hindu succession act intestate succession in female no judgements required. Feel free to contact in case of any difficulty