Conversation so far:
What was two super girl's meet?
Prior to the post-Crisis introduction of Kara Zor-El into mainstream continuity, the pre-Crisis Kara Zor-El made.
What was Kara role in Super girls Meet?
Supergirl.
What was the story-line of the show?
The paradox becomes a moral crisis for Linda who tries to take her place as the Crisis sacrifice, living for years in a Silver Age universe where "no one swears.
When did the series come out?
2001.
What other things happened during this series with Super-girls?
Linda's inability to ultimately save Kara is so devastating that it ends her own career as Supergirl.

Question: Why did it end her career?
Self-contained rewrite: Why did inability to save Kara end Linda's career in Two Supergirls meet?