They are definately silkies, pretty too.
I'd say more than likely the last two are roo's....BUT silkies that don't have much or no topknot tend to have the warting as I call it...and until they mature a bit more and get fuller waddles or not and the comb grows out more warts and turns a brighter shade then you may have a hen(s)...
Silkies that are bought from
Tractor Supply, any feed store, and a lot of hatcheries are a real mixed bag, you can get some very beautiful birds that are close if not right spot on show quality...but most are beardless or topknot-less or have too many toes, or the toes are not the 'correct formation' for a silkie....Some have little to no warting even roo's and some females will get a bunch of warty combs on their heads if they don't have a good topknot...So you dont really know.
I have silkies as pets but some of mine are show birds, of show stock, getting some hatchery silkies soon... and i've had all sorts of silkie mixes in the past. I don't care, though I need a new roo! I lost my male roo to a misfortunate little accident about a month ago, and so am searching for a new one.
Silkies = awesome birds all around, beautiful, fuzzy, smallish, tend to be non aggressive, and great pets. G'luck with your guys and gals.