Gift deed under HUF

Aman kocher (Manager) (21 Points)

15 July 2023  

Mr X , his wife Y and 2 sons Z&A 

Mr X has a property under HUF , X dies & by the way of will property transfered to Z&A 

after few years Z&A transferred their property to Mother Y by gift deed and mother gift property to her sister by gift deed  Can she do that and is it legally valid in law