Depending on the situation involved here (answering a question for example or some other thing), the translation in Arabic may vary. But as a simple form of that sentence, it would be: صديقتها هي كري (her friend/she/Carrie).
and I don't know where from did they get such a name
I keep hearing "Sadiiqatuhaa" for "صَديقَتها", even though it seems to be spelled "Sadiiqathaa". Is this an error or am I missing something?