Carniele is not particularly strong in the One Power. Her level of strength is described by "The Wheel of Time Companion" as 22(10) which is a middle/high level in Aes Sedai hierarchy. This level of strength can be just enough to open alone a suitable gateway to Travel.
She has remained loyal to the White Tower during the schism.
Carniele was involved in the disastrous attack on the Black Tower led by Toveine Gazal on Elaida's orders. All fifty one sisters involved were captured and bonded by Asha'man. It is not known who Carniele was bonded to.