In your sentence, the adjective is attributive not predicative. I see you are learning German so maybe I can give you an example in German:
- meine Tochter ist gut (my daughter is good) - adjective in predicative state.
- meine gute Tochter (my good daughter) - adjective is in attributive state.
In Arabic, attributive adjectives must mimic the noun they follow and describe in everything (number, gender, and definition). In the sentence above, the adjective is not defined, while ابنتي (my daughter) is defined by the virtue of adding the suffix ـي (my) to it (just like in English, you can't say the my daughter because my daughter is already defined without "the"). For this reason we conclude that the adjective is predicative because it didn't follow the noun, and hence in English there must be a verb (to be) to connect the subject and the predicative (my daughter IS amazing).
Your sentence, my amazing daughter, would rather be ابنتي الممتازة (ibnatí al-mumtázah). We defined the adjective here to follow the noun in status.
Bonus: بنتي is rather dialectical, and the correct form in standard Arabic is ابنتي. And amazing is rather مدهشة or مذهلة but NOT ممتازة. This word means excellent.
Things in Arabic are not as in English. A man talking about his own daughter wouldn't usually use the word "girl" (فتاة). But rather the word "Daughter" (بنت).
I know, here on Duolingo there are using the word Bint for general, either girl or a daughter in some other context, and I have to say, this is kind of a dialectical usage. Not a professional proper Arabic.