Silkies are notoriously tricky to sex as youngsters! some can keep you guessing for months! with no other siblings for you to compare it too, you may have your work cuut out, at least for the next few weeks at least.
Generally speaking, young Silky males are larger than their sisters, longer in the leg and with with bigger feet. If they are of the beardless variety they will bhgin to show greater wattle growth, and a larger patch of roughened skin where their combs will be as adults. They will also eventually begin to grow ' streamers' in their crests, long pointed hackle-like feathers that will give them a slightly windswept appearance rather than the females neater and more compact crest. youung males' voices will also be deeper, and slightly hoarse, whilst their sisters retain their high pitched chick-like 'cheep' for longer.
Judging by this bird's colour, i'd imagine it is either a gold or partridge Silky, or a coss between the two. With this in mind, if it is male, as it grows it will probably show a much darker red shade in it's shoulders and saddle, females remain a much paler and more subtle shade of buff.