Irina Lucidi has appealed for tips from anyone who might have seen the twins, who went missing Jan. 30.
Speaking to journalists at a brief news conference in the Corsican capital Ajaccio, on Sunday, Lucidi said she'd taken part in investigators' helicopter fly overs of the island. She didn't provide any additional details.
Hope of finding the girls alive is fading after a letter from their father turned up declaring he'd killed them. The father, Matthias Kaspar Schepp, killed himself in Italy after taking the twins to Corsica. He left the island alone.