Gift deed of CITB site to daughter before BDA sale deed

Mother has been allotted site from CITB in 1969. Daughter has been allotted adjacent site from CITB in 1969. Both on lease cum sale basis. Possession certificate is given to both of them. Mother has given a gift deed of her site to daughter in 1970. This is registered in sub-registrar's office in 1970. BDA has issued absolute sale deed and khata certificate in mother's name for her site and another absolute sale deed+ khata certificate in daughter name for her site in 1980. In 1981, daughter has transferred khata of mother's site to her name. She has gone ahead and sold both the sites to a 3rd party. Is this possible? Is the daughter the owner of mothers site as well? The absolute sale deed to 3rd party does not have LTM of mother, is this fine ? Hindu