>>30146783More speculation than anything else. Just seems a bit odd that she didn't become a Trail captain if she was below 20 and trying to impress the Tapu's.
She didn't even do the Trials herself either. She just soul searched a bit.
I also assume and a Kahuna needs to be both mature in mind and body in order to keep the Captain's in line and guide them, since all of the other Kahuna's are clearly above 20 themselves.