Hollande, 59, has split with longstanding partner Trierweiler, 48, after press revelations of his affair with 41-year-old actress Julie Gayet. Trierweiler was hospitalised for a week after news broke of Hollande's involvement with Gayet, and she had since then been holed up in a presidential retreat outside Paris.
Trierweiler, who was treated in hospital for a bout of "tiredness" brought on by the scandal, had been invited to India in her official capacity.
The charity is paying for the long-planned trip, which is financed mostly by private Indian partners.
Trierweiler visited India in February last year when, accompanied by the president, she visited a shelter for street children in New Delhi and spoke of her desire to become a champion of children's rights.
India at the time decided to treat Trierweiler as if she were Hollande's wife, resolving a potential protocol headache in the conservative country.