Love my SizzlesUsually when they say F3 that means the third generation bred back to get correct genetics. I believe she is a Sizzle and not a Silkie. She has smooth feathers, so somewhere in her breeding she lost one silkied feather gene (perhaps on purpose) while gaining that frizzle gene - its hiding under there but she isn't a "Silkie" as long as those feathers aren't Silkied... Your darker one looks like a Frizzled Silkie (got two Silkied genes) so she can be called a Silkie again as long as everything else is correct.
I have a Sizzle too - goofy bird! They started out as a cross between a Frizzled Cochin (or other bantam who was Frizzled, I heard some used Polish) and then crossed back to Silkies again to get the toes, skin, ears, combs, etc. correct again.
PS that white hen is gorgeous!
Caffeine or Caffy if it's a girl.