Suspect silkie crossed with leghorn only because leghorns are very common and that coloring is very typical of white leghorn crossed with a colored chicken.
If you breed them together, and get Paint patterned birds(mostly white with black patches), then paint silkie cross would be right answer. If most are like this with some being solid white and some with no white then it's probably leghorn cross.
Thanks, I have a crazy crossbred bantam flock and I just had a few birds given to me that are absolute mysteries LOL they are a fun side project gone mad
Hard to sex from those pictures, sorry. At this age the boys should have plenty of shiny and pointy tipped feathers on the back by tail, neck and in crest.
In the last picture, it kind of seems the closer one might be a boy(seems to have the rooster sickle tail feathers by the tail) and the one behind is a girl..
There should be crowing and eggs in a few weeks.. they seem almost point of lay age.