She was an indescribably unique person.
She was indescribably unique.
Unexplainably(indefinably) unique. That’s how I’d describe her.
Initially I wrote as the first one, and then I thought 'A is a(n) ~ person' is a bit awkward, cause A is definetely a person, so I changed it to the second one.
But then again, what I want to emphasize here is that she is 'indescribably unique that it's hard to describe her', and in English we put the part we wanna emphasize at the beginning of the sentence. So I finally changed it to the third one. (I changed the adverb cause I have to repeat 'describe' if I use indescribably..)
But I thought it's unnecessary to divide the sentence in two, and I'm still not sure which one among those three is the most natural one in the eyes of native speakers.