To have Phaere's portrait appearing when you speak to her as a non-party member, you need to
1) change the portrait size to 38x60 pixels (you may use the one I've attached to this post) and place it in override folder
2) edit Phaere's creature files (udphae01.cre and udphae02.cre are the two that I know of) to reference the created BMP portrait. (whatever you named it; UDPHAES if you use the attached here)
The easiest way to edit CRE files is using DLTCEP