Gift received

1. As per sec 56(2)(x), any gift received where the monetary value of such gift or cash amount exceeds Rs. 50,000 during the year then the entire amount will be subject to tax under the head Income from other sources. 
2. However, the above provision will not be applicable if the gift is received from relatives.
3. In your case, brother will be considered as relative for the purpose of sec 56(2)(x). Gift received by the sister will not be taxable in her hands during the year. 
Please correct me if the above solution has an alternative view.