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!