As per Sections 8 and 12 of the Hindu Adoptions and maintenance Act, 1956, (‘HAMA Act', for short) the widow of a Hindu male is competent to adopt a son or a daughter without there being a direction/expression of desire to that effect, by her deceased husband. That the effect of adoption by a widow would be that the child so adopted would be deemed to be the child of her deceased husband also.
Hindu Adoptions and Maintenance Act, 1956 S. 8 and 12
Vijayalakshmamma v. B.T. Shankar, (2001) 4 SCC 558 : (AIR 2001 SC 1424)