Kari, Tai's little sister.
She appears for the first time in the 21st episode, but if you are referring about the episode the Digidestined find out she was the eighth child all along it happened in the 34th episode.
It was never shown. She is one of the few female Digidestined in the cast to not have a confirmed husband, the other being Mimi.
there are 8 crests courage = tai sincerity = mimi friendship = matt love = sora hope = tk light = kari knowledge = izzy reliability = joe
Gatomon was originally chosen to be the Digimon for the eighth Digidestined child (which turned out to be Kari) but her YukimiBotamon Egg was dropped and she grew up away from the other seven Chosen Digimon and eventually was found by Myotismon and he decided to have her work for him for his own villainous purposes.
Kari Richards goes by "Scary Kari".
Kari Baumann goes by Kari Sue.
The Golden Digimentals movie is non-canon because it features lots of continuity errors that makes this movie unable to fit anywhere in the Digimon Adventure chronology. It is supposed to happen when Ken is still not a member of the group and the Digidestined are still relying on Armor Digivolutions. During this time the previous group of Digidestined are not supposed to be able to evolve past the Champion level because they sacrificed the crests after the Diaboromon movie, yet the movie ignores that and TK and Kari are able to evolve their partners all the way to the Mega level. The previous Digidestined should only be able to regain this power after Azulongmon supercharges them, something that only happens after Ken joins the group. The fact Patamon and Gatomon went to their Mega forms is also a problem because in the final battle against MaloMyotismon the Digidestined used the power of the wish dimmension to evolve into every single one of their forms and Seraphimon and Magnadramon were not present there, meaning they didn't have that power when they did that.
Kari Michaelsen's birth name is Markusen, Kari.
Kari Hagar's birth name is Kari Karte.
Kari Jobe's band is just called Kari Jobe.
Kari Tuomisaari's birth name is Kari Kustaa Tuomisaari.