"My friend Judy is smart."
Translation:صَديقَتي جودي ذَكِيّة.
Farshid199181, because Judy is a female friend صديقة and not male. So, the predicative adj. (خبر) should be feminine also ذكية.
صديقتي جودي ذكية
"My friend, ie. Judy, is smart."
Or if the subject صديق is masculine, then its predicative adj. (خبر) is masculine ذكي. For example,
صديقي بوب ذكي
"My friend, ie. Bob, is smart".
Nb: I have updated my comment. Previously I wrote "object " instead of "predicative adj." as I didn't know the English term for "خبر" at that time. Whilst, if I wrote the explanation with the Arabic terms, people wouldn't understand either. So, it was dilemma for me. Hope it is better now :))