Wow that is a tough one, they really both do look like males! Of the two I'd say the naked neck is more masculine looking and the other is the more likely culprit but I'm seeing streamers on both which I have yet to see on a female.
Luckily there is an easy way to tell if one is laying. Right below the vent there are two pointy pelvic bones. In a male or a young pullet that isn't close to laying these bones will be very close together. The bones spread apart to allow enough room for eggs to be laid once a pullet gets close to laying. If you gently feel below the vent you should be able to fairly easily find these bones, they are quite distinct/pointy. Sometimes in my laying girls the pelvic bones that have already spread apart are closer to either side of the vent rather than below. In males I often can't fit even one finger width between the pelvic bones (my fingers being probably medium width for a female). When I feel the pelvic bones of my pullets that are about to start laying I can fit at least two fingers width between the pelvic bones.
If both have pelvic bones that are very close together it is very unlikely the eggs came from them.
I'm very curious about what you find! I've heard from a couple people they've seen silkie pullets/hens with streamers before but I have never actually seen anyone post a picture of a female silkie with streamers. Both of your silkies look to have pretty prominent streamers so if one is actually female it's definitely going to make me a believer!
