With mix breeds it is simple to hard to tell ,you just have to give it time. It is the chance we take when hatching or getting mixed breed chicks.Plenty of neutral names you can give them.
http://www.dogs-day.com/gender-neutral-dog-names/gender-neutral-dog-names-a-z...
Sorry they are not as fluffy as they should be. Just hatchery stock. I really don't know how to tell type on cochins I have only had them since spring.
Unless you know what breeds and sex of both parents feather sexing will not work. Fast feathering female to a slow feathering male.
is possible in crossbred chicks bred for that purpose.
http://scratchcradle.wordpress.com/2012/04/19/chick-sexing-techniques/
I agree she looks Orpington could be a buff Orpington over black Orpington. One may never know but as long as you like her guess it does not matter what she is.
The hens are sex links ,in your country they are more then likely Isa Browns.
The Australorps it's still hard to tell but the one by its self looks to be growing it's wattle faster but still not sure wait a few weeks the difference should be obvious by then.
Wow it really changed a lot from the second picture to the last picture or was that an older picture. It sure confused me as it is from the last picture a brown leghorn.
Probably some ones hatchery stock cochins breeding with different cochin colors. So you have cochins just mixed colors and hatchery stock. Only time will tell this age they look the worse.