There was a post of this but I cannot find it. I found Choixth at Russafeld Heights Wayshrine. Just teleport from a different wayshrine back and forth to Russafeld and do it like 5 times. I got lucky and got it 5 times in a row doing this method. Also, Choixth is on the right side of the wayshrine when you spawn you will hear her and Bailiff talking.