And Egwene is nearly 2x Moiraine. This is essentially a theory I put forth several years ago. I started with Daigian being. 16, other than that it's pretty much identical.

Edit: and does you Math work downward toward Morgase for 6SD? There are several women in those levels as well and we know there must be as many SD between Mean and Morgase as there are between Lanfear and Morgase. Your SD is too large for the Mean to located at 16.6 and allow for a 0 or 1 minimum. It works better when you have Daigian at a 16, Mean around 24 and Egwene 80 meaning 4SDs with the a forsaken all falling at various places in the 5th SD.

On the reverse side this still doesn't work as the SD you've calculated is too large for a Mean so low. Here is the problem, on a fixed scale measuring Lanfear to Morgase with 6 SD the spread of each SD will be 16.5. This is based on your math above with Lanfear at 100 and Morgase at 1. This makes the Mean 3 SD above Morgase and 3 below Lanfear. Roughly 49.5, but still does not work perfectly because Daigian is vastly too weak to be within 1 SD. So we must assume we can ignore that in order to place her with some accuracy, but it needs to be within a reasonable range for her to be accepted. If we place her 2 SDs above Morgase at a level 16.5 that gives us many levels for various AS leading up to the Mean, and still keeps the levels above the mean reasonably populated (especially if we look to New Spring AS and other groups of women)

However, if you accept that Moiraine is at Mean, in this case a 49.5 we can actually make this work. 1 SD up you may find Cadsuane around a 66, 1 SD down you find Verin around a 33. 2 up around an 80 is Egwene and 2 down you have Daigian at 16. 3 up are the Forsaken and 3 down is Morgase.

This squares with other RJ quotes of how the AS cover more levels than we thought and allows for a BC with the same number of Standard Deviations between Morgase and the Mean and Lanfear and the Mean.