Inheritance rights of a childless hindu female widow

Your brother's wife inherits all the rights of her husband on the self-acquired property of her husband and his inherited property.  Your mother is entitled to equal share of her son's properties with other co-sharers if your brother died intestate.

Thank you Prasad Sir. 

I am not sure about the validity of the bellow article. As per it, the widow is entitled to have her husband share only if her husband dies before the father-in-law. In our case, my brother dies after my father. 

https://www.legalkart.com/legal-blog/widow's-rights-in-a-father-in-law's-property

I also understand that a childless widow cannot claim the entire share of her late husband, but half of it. For example, if the late husband is entitled 1/4th, then his widow has rights on 1/8th. Is it true?

Ye, your assumption is correct. The late father's property was jointly vested with the mother and the siblings, including the deceased brother. On the death of the brother his share of property is jointly vested with the mother and the wife of the deceased.

Mother and widow have equal share in the self-acquired property of deceased (son/husband).

The widow shall have share of her pre-deceased husband in the intestate property left behind by her father-in-law.

Article quoted is not opening.

Instead of making mess of queries it should be subject-wise.