Question: Was Talia ever mentioned about after the placed personality took over and she left?
Question: What did Susan do after she left at the end of season 4?
Chosen answer: She was promoted to Captain and thus had to leave Babylon 5, becoming a captain on a new Warlock class ship. Later on she retires/quits and becomes the top Ranger on Minbar.
Answer: She was promoted to Captain and headed a new class of ship called the Warlock. Hence she was no longer on the station after season 4, dealing with her grief from Marcus dying.
Answer: According to Babylon 5 lore, PSI Cop Bester was quoted, "We learned some interesting things about Ms. Winters in the course of her debriefing and dissect-that is, examination.