Board Thread:Theories and Speculation/@comment-1512913-20161125200227/@comment-1512913-20161129143630

Well, Kaguya might have possibly had the power or potential to awaken the Tenseigan, or she already did for all we know, just didn't use it for plot reasons, which is quite possible, just like Obito couldn't use Kamui or Madara wasn't using his power more prominently (spamming Tengai Shinsei while alive and TT jinch, using Susanoo etc.) towards the end the characters got nerfs or restrictions to make it manageable.

In case it's the first option and she didn't have it, then it's possible that there might be some special condition required to awaken the Tenseigan, just like there is a condition for Mangekyou Sharingan.