If I recall well, you can't rise stats beyond +10 by any natural or magical means.
We'd be assuming that Ness has a rather nice WIS 15 to begin with, and she'll be steadily gaining a +1 every other day, over the the next 20 days...
...
As we all know, Ness has a rather respectable INT 15, but from her log we can easily surmise her to have a quite lower WIS 10, or even less.
This means she cannot possibly rise to WIS 25 in no conceivable amount of time.
Therefore, if she's got a WIS 15, she's not actually Ness but a Doppelganger under disguise, and I suggest we tickled her to know the whereabouts of the real Nessie's body, so we can resurrect her before the carcass decays off.
...
Pronto.