At their age there is no way to ascertain their quality for showing. I'd recommend that you connect with the breeder you got them from and ask lots of questions. Ask him/her to go over her adult birds with you and point out the traits you want as well as showing you traits you want to avoid. Not just DQs and faults, but the ideal for head, crest, eyes, body shape, carrriage, wings, etc., etc., etc. Volunteer to help them get birds ready for showing so that you can learn what you need to do. Some things are breed specific-if you prepped a silkie the same as you would an OEGB or RIR, the silkie would not look its best--it is a very soft feathered, fluffy breed, as compared with very hard feathered breeds.
Try to attend some shows while you are waiting for your birds to mature. Ask lots of questions, look at the birds and try to understand why they place as they do in judging. Ask the judge to go over with you what they are looking for. If you're lucky, there will be several silkie breeders and you might get to listen in on lively discussions about different breeders opinions--and you can learn from that.
Good luck, and have fun!