Board Thread:Questions and Answers/@comment-120.169.254.238-20160725234801/@comment-26447088-20160726022237

At the start of a quest (on the first wave), there's a chance it will awaken like any other Passive skill. However, unlike other normal Passives, the awakening window is restricted to only the first wave of a quest when Passives get a chance to trigger.

Loyalty also plays a factor into how likely she'll awaken her Unique; the more Loyalty she has, the higher chances there are that it'll awaken.