Section 22(8)(b) in All India Services (Death-Cum-Retirement Benefits) Rules, 1958
(b)Where the deceased member of service or pensioner is survived by a widow but has left behind eligible child or children from another wife who is not alive, the eligible child or children shall be entitled to the share of family pension which the mother would have received if she had been alive, at the time of the death of the member of service or pensioner.