I'm not sure if it's because Sofia's player is just blind or not, but this has not been possible with Verdis Elementum. Our highest-ranking elder is about rank 5 or 6 I think, and has been unable to claim a better rank.
I've checked out the situation on the dev server, and it looks like she should be able to access it.
The sequence is this:
Visit Verdis Elementum temple
Manage Ranks
Scroll to the very bottom, and you should see this line:
As there are no elder members in ranks above yours, you can
reclaim the ranks above yours, making the rank you currently hold the highest rank in the order.
Click on the "reclaim the ranks" link.
