Family pension and death gratuity - not eligible as receiving two other pensions?

My brother was working as Associate professor in a UGC affiliated central university and expired before two years.His first legal heir , his wife and second one his daughter have relinquished all of their rights on his family pension and death gratuity in favour of our mother.The university approved it ,but now says that as our mother get her own service pension and her husband's family pension (both were in state service)she is not eligible to receive family pension and gratuity from the university. I would like to know even if she is not eligible to receive two family pensions
Whether she has a right on the gratuity.

Hi there
First of all , it is better to know, on whose name the nomination is given by your brother. ( mother or wife)?/
In general, most of them change their nomination to his wife and family members, once married. So what has happened here is not known.
Gratuity is payable to dependents , as per nomination.
I am afraid, i cannot comment on the pension part