Board Thread:Speculation House/@comment-33053086-20171210163906/@comment-4010415-20171212035012

All we know for sure is that Qrow said "a single look" from a Silver-Eyed Warrior could "strike a Grimm down", and sure enough, Ruby petrified a giant dragon Grimm.

It's possible that silver eyes also affect Maidens, but it's also possible that Cinder was only affected because she used a Grimm to steal the Fall Maiden powers and seems to have that Grimm beetle inside of her.