Sporting a youth-oriented 90s look, this Kara comes with the usual impatience of a new young hero, but also a duty of responsibility and common sense.
Let's take a look and see what happened:
Superman, while on a trip through space, discovers the lost colony of Argo (this time a planet instead of a city). The only living survivor of this planet, like Kal-El, is Kara, a young woman. Since she is from the same planetary system as Kal-El, Kara's body takes on the same powers when she comes to live on Earth with Ma and Pa Kent (a lá Matrix).
Skip ahead a bit and the young Kara comes to visit Clark in Metropolis, posing as his niece. At the same time, Jimmy Olsen is looking for a scoop to prove his abilities as a reporter. When Jimmy and Kara hook up, Wham! It's non-stop action for the rest of the episodes. Supergirl not only confronts Intergang, but also the minions of Apokalips, including the Evil One himself, Darkseid. Oh, and she also saves Superman. What a show.
What makes these episodes work more than anything is that Kara is not dull. While the introductions of Steel and Maxima seemed more humdrum earlier in the season, Kara is constantly in motion and keeps your attention the entire forty-plus minutes of show.
One final thought - I would have liked to see a little more of an origin for this Supergirl than a jump from a hypersleep chamber to the Kent farm. Maybe a shot of her sewing the "S" on that cute little shirt of hers.