If the owner of the property is reported to have died intestate then as per Indian succession act,  the widow shall be entitled to one third share of the property and remaining two thirds will go to lineal descendants. 

Here the minor children are considered to be lineal descendants. 

The widow can sell only her share of property,  if she as a natural guardian and for the welfare of the children wants to sell their share of property property along with her share then she may have to obtain permission from court to sell it on their behalf. 

The old sale agreement is valid but the sale deed can be executed by all the legal heirs together and not by only one among them. 

If it's her self acquired property she can sell it

Property should be mutated in favour of widow and 2 minor children 

2) further court permission is necessary for sale  of minor share in property 

3) court would grant permission provided minor share in sale proceeds is placed in fixed deposit 

Under the law of inheritance applicable to Indian Christians, widow is entitled to inherit one third estate of deceased husband and children of deceased father take two third. As children are minor, it is safer to obtain permission from Chief Judge City Civil Court, Hyderabad  to purchase 2/3rd share of children. No such permission is required for purchasing 1/3rd share of wife. Parents will not acquire any right in the property but obtain their signatures on agreement. Execute a fresh agreement after mutation  of property in name of widow. 

After the intestate death of that person, all his legal heirs, widow, minor children and parents shall inherit his self-earned property. As minors' interests are involved, the major legal heirs can sell the property only after getting a court order for that purpose. Please be guided accordingly.

- As per law, the right of a a Christian Wife  , to get share in Property is governed under the Indian Succession Act

- Further, if the husband died leaving behind children then the wife will get one-third share and remaining two-third share will be distributed among all children.
- Hence, after the death of seller , his property would be devolved upon his wife and children , and the wife can become the single owner of the property only after getting order from the court , as both children are minor. 

Dear Client,

               The Christian law of inheritance and succession is the same for men and women. A person's property is treated as self-acquired despite the mode of acquisition and during one's lifetime, nobody else can contest for it.Property rights of Christians in India is governed by the Indian Succession Act, 1925.The Christian law of inheritance and succession is the same for men and women. A person's property is treated as self-acquired despite the mode of acquisition and during one's lifetime, nobody else can contest for it.A widow cannot succeed to the property of an intestate (someone who has died without a will) if a valid contract, made before her marriage prohibits her from succeeding to a share in her husband's property. In normal cases, the property of a deceased devolves upon the wife/husband or upon the kindred.When the deceased leaves behind a widow and children, one-third of the property shall go to the widow and two-thirds to be distributed among his legal heirs.

A Christian man can legally marry a second time only upon the death of the first wife or after legally divorcing her. If he has a second wife while his first wife is still living or is not divorced, the second wife or children borne of her will have no right on the man's property. Otherwise, only the first wife and her children have the full right over it.Do note that the children of a legally divorced wife have an equal share over their father's property as that of a second wife and her children.

Thanks & Regards