I'd say that you'll have to wait a few weeks before trying to figure out the sex.
Where did they come from? Did you buy eggs or did the hen lay them? Maybe you got an odd egg that is some other breed?
Hi, we bought the eggs at a farmers market for our broody Dorking to sit on. They were all from 1 batch bought which were described as French Maran eggs- was wondering if this was a type of Maran chick or not???
They may have meant French Black Copper Marans (like in my avatar). There is - I believe - a white marans variety... But that chick looks to be a lot bigger than it's hatch-mates. If possible, maybe contact the seller and ask if they have any other breeds that one egg may have come from. Were they all very dark brown eggs? Either way - it's a cutie. Enjoy having chicks - they're a hoot!