"She is also a pretty woman."
Translation:Είναι επίσης όμορφη γυναίκα.
Duo's sentence stresses the fact that she among other things is also a pretty woman. The sentences you suggest stress the person, not the characteristic (that is, suggesting there is one pretty woman, and the "she" in this sentence is also beautiful, making two pretty women).
It would be like "She, too, is a pretty woman", i.e. "[not only that other person but] also she is a pretty woman"
Hm, I'd say that the difference between ωραίος and όμορφος is almost the same with the one between nice and beautiful/handsome in English. Ωραίος could actually refer to character as well, while pretty/handsome/beautiful usually refer to a man's or woman's appearance (or an object's appearance.).
Not that beautiful wouldn't be used to describe character in English, but I feel like it would sound kind of odd in Greek.
In other words, ωραίος could mean όμορφος, but it's a bit more generally used. (In my opinion, at least ^.^)
Or, further to that, instead of "nice", we might say "fine" in this context. Examples would be, "He is a fine young man." or, "She is a fine young girl." And from interacting with my Greek friends and relatives, this is what they mean by ωραίος when used to describe a person in such a way. It is not really the external looks, but the overall character of the person they are complimenting.
Why is επίσης placed in the beginning of the sentence here and in another sentence at the end? I understand that in English 'also' and 'too' have specific positions, but for greek it was the same word I think.