The first movie is set during summer. Koda said they spent 6 months hybernating, so Koda is about 1,5 years old, more than enough to a grisly bear become adult and have a life of his own. Kenai could become human again and put in Nita.
shareUhhh....I think Disney wanted to keep Koda as a cub cause Jeremy Suarez took a slow pacing time for his voice to change when he was working on this. Either way, Nita and Kenai would of still hook up together whether they were humans or bears. I'm not really sure what those two would do if Koda had reach adulthood by then.
I am who I am, you can't change that!