Board Thread:Episode Discussions/@comment-25319479-20160512105958/@comment-734582-20160512160355

Not every Otsutsuki has Byakugan. The ones on the moon were Hamura's descendants (and thus had Byakugan).

Also note that the Chakra Edibles as shown in Boruto The Movie can easily explain why she could do what she did. Including that it heavily implies the Shinju was planted on this world by the Otsutsuki, and that Kaguya was simply meant to guard it.

With those Edibles (of the permanent kind) Kaguya could've taken the Byakugan portion of her home's Shinju fruit and Kinshiki and Momoshiki the Rinnegan portion (with the Rinnegan mostly in Momoshiki's possession and only weakly in Kinshiki's).