She mentions that she, Egwene and Aviendha have the same potential, though Egwene has already realized her full strength due to being forced by the Seanchan training methodology. Egwene is still the strongest of the three because of this.

Forcing makes a channeler reach their full strength quite quickly, so they fulfill their potential earlier.

Note, however, that the old "Saidar Strength List" actually placed Aviendha, Egwene and Elayne right below Moghedien, so it appears that this was quite accurate, especially if we are talking about a head-to-head battle with the One Power where raw strength is an advantage.