1) Yes it does look like coturnix to me
2) the slightly rust-ish colour on the breast suggests male, also the lack of speckles, which you see on a hen. I'd say there's a good chance it's a male. However, sometimes the different colours male it difficult to tell gender.
Watch out for crowing, is he/she in with hens? If so, try separating them, that usually causes a male to crow. Obviously if it lays an egg it's female. Also watch out for mating and other sounds, for instance if one of my hens gets separated from her friends she makes a little cricket chirping noise, and if the male finds mealworms he makes a clucking sound like a chicken.