Me personally am very happy with this fortune!
But you might wait for a while: In the quest 'sister, sister' Greselda says she wants to re-evaluate in 3 months. That's now. Maybe there's something happening in one of the next updates.....?! Maybe she'll be satisfied with all the inscriptions we've made so far....? Just speculating, of course.
And remember, when you buy the fortune teller tent, there are lots of fortunes to be done before you reach the glimmer rock-one (it won't take months, but still).
And Roguebee is right: once you finish 'a little persuasion' the inscriptions for that still stand, you can use them afterwards for 'sister,sister'! (not the other way round, though, so first complete 'a little persuasion'!)