It is an unusual way to say it, but I wouldn't call it wrong.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
DaithyPetra is my friend. She has been 35 years of age."That would be a slightly different situation, so you wouldn't say that. You would say she is 35 years of age, or if you were talking of a moment in the past you would say she was 35 years of age.