It was stated the baby's name was Kopa at the end of the first movie? No.
The creators said its name was Fluffy, a cub with no gender. They didn't want to contunue the story, why bother with the name or sex, it's useless. Kopa appeared in the BOOKS, Kiara was created by SP's staff.
Even today after the books and the sequel, the directors say the cub's name is Fluffy, not Kopa or Kiara. They don't acknowledge both of them.
It's simple:
1- TLK came first (Fluffy)
2 - The books came after TLK (Kopa)
3 - SP came after TLK and the books (Kiara)
4 - Even today, the original creators deny both books and sequel (Kopa and Kiara)
So, the timeline is:
1 - Fluffy
2 - Kopa
3 - Kiara
Fluffy came first, he/she is the original one.