That's a lot of kids! But it's so awesome that you're able to give them all a loving home. :) I've seen situations where older foster children that are adopted
want to change their name, like a new start = new name. So I'd leave it up to her, really. I definitely wouldn't just pick something and start calling her that, but that's not what you're suggesting at all anyway. If she's attached to
Cora, though, I agree with other posters that yes, it will be confusing for a while but everyone will adjust. Also, you could (if she's willing) call
Kiara "
Kiki" sometimes to distinguish between the two.