Translation:She is pretty.
かのじよ is ambiguous to age, you wouldnt call a ten year old girl a woman.
True, but my point is that the word in this sentence is the pronoun 彼女 (かのじょ), not the noun 女 (おんな) - so it should be translated as "she" or "her", not "the girl/woman".
It is true that girlfriend is listed as one of the proper translations of the word, but I think that, for the most part, it's a pronoun.
I said "she is clean" since I just did a question about clothes bring kirei, meaning clean. It was mashed incorrect, but can the definition of clean people or beautiful clothes apply either way?
Are you sure? There are plenty of resources online showing "きれい" being used to indicate people and parts of their bodies etc. being clean. So I don't see why "she is clean" is not a valid translation, even if it's not the most likely one (せいけつ is probably the word that would be used).
In class I was told that きれい doesn't really work for people. Is there a better way to say this?