Marthe Ngo Sing appears to be a Cameroonian actress. The strongest current evidence I found is her credit in the Cameroonian drama film MIA (2025), directed and produced by Prosper Tekam. The film is listed as originating from Cameroon and in French, with Marthe Ngo Sing credited as an actress alongside Sacky Monlea, Marie-France Agoume, Edith Tekam, and Ferrant Hatou.