Conversation so far:
When did he reunite with Lilith and Frederick?
In "The Show Where Lilith Comes Back" (1994), Lilith surprises Frasier by dialing to the radio show.
What does she say on the radio show?
They later make love in a hotel room, but end up regretting it, prompting them to part ways again.
Is he reunited with Frederick?
They decide to remain friends and help each other raise their son Frederick (Trevor Einhorn), who also appears occasionally in this spin-off.
Does Frasier have a good relationship with Frederick?
Frasier is proven as unathletic and bad at softball, which he reluctantly admits to Frederick.
What else happens in the reunion episode?
In "Adventures in Paradise, Part Two" (1994), Lilith gets engaged to her fiance Brian (James Morrison), much to Frasier's dismay.
How does Frasier react to the engagement?
dismay.
How does the episode end?
Lilith last appears in "Guns 'N Neuroses" (2003), in which she Frasier are accidentally set up to go on a blind date.
What happens on the date?
Lilith and Frasier are close to restarting a relationship in the hotel room, but they are interrupted by a loud argument between a young married couple.
What is the argument about?
Frasier and Lilith are able to resolve the couple's dispute, spend the night together watching television, and finally fall asleep on the couch without intimacy.
Do Frasier and Lilith see each other again?
The next morning, they part ways at their final onscreen moment together.

Question: Is this the last episode she appears in?
Self-contained rewrite: Is "Guns 'N Neuroses" the last Frasier episode Lilith appears in?