Chicken Integration concerns

[Asliter]

Hello all!
A few months ago I hatched some new Americanas for the first time! About a month ago I began the process of integrating them into my existing flock of two leghorns and an Austalorp. I have separate feeders and plenty of places for them to hide. It seems however the newcomers are still terrified of the order girls even though they are about the same size. My question is how long before I can expect them to warm up to one another? I have a temporary second coop in the run the newcomers prefer to stay in but I was hoping they would all move into the permanent coop by now. I didn’t want to rush anything but I also don’t want to keep the separate coop forever because it does not have nesting boxes.
Also I think a couple of the newcomers are cockerels judging by there longer tail feathers. I’m thinking they will be the first to stand their ground to the older girls.

 

[RodNTN]

As long as the newcomers always have access to food and water, they will be fine. They'll warm up sooner or later

 

[Ridgerunner]

Pullets will remain separated until they mature enough to force their way into the pecking order. That's normal. There is a good chance the older hens will show them where to lay even if they are not sleeping in that building as long as they have full access. I know you read about size all the time on here but from my experience size does not matter, maturity does. Mine merge into one flock about the time they start to lay.

If you can post photos of the two in question, a head shot showing comb and wattles and a different profile shot showing legs, posture, and tails we may be able to help you with their sex.