No she cannot sell without your consent and noc. She can't deny the share also
The hindu succession Act is very clear about the same if the property was received by her from her father during marriage then the class one heir will be her father side and not her husband and children. Here I have assumed that there is no one to claim from her father side as no information is given above the legal heirs that is her children will also have share in it. Unless and until the same is received by her through will. If there was a will of her father it will be devolved as per will. Otherwise legal heirs will have their right and your mother will not have exclusive rights. Here the class one heirs will be her brothers and sisters and not her children
Your rights will only come if no one claims from her fathers side