i would say it is way to early to tell what gender
i have tried the feather method before and i got it completely wrong thought i had 10 girls out of tweleve chicks (which i did think was weird you never get that good luck when hatching) and ened up with only 4 girls!! and 8 boys!!
i would wait till she/he is older
sorry to be no help
Feather sexing is not an accurate way to sex chicks. Your best bet is to wait until they are 4-8 weeks old and look at the comb and wattle development.