You are entitled you your opinion. Beauty is in the eye of the beholder. Many people saw her as beautiful. No doubt, there are people who would agree with you. It's also possible the standard of judgment is different because she was black....a black woman with primarily white features.
She had a level of grace that made her beautiful on the inside as well.
She was, as is often the case, a mixture of the so-called "races". And to mine eyes, a rare beauty. In much the same way that Johnny Mathis (and most, if not all, his immediate family) was very good looking in his youth, so to was Miss Horne. I enjoy much of her singing but my favorite female vocalists remain beautiful Ella Fitzgerald and the loverly Karen Carpenter. In that order. Depending upon material, Karen can equal or surpass Ella but they are 1 and 2 on my Hit Parade.
Beauty is in the eye of the beholder but the soul that is formed in the hand of God, as most assuredly was Ella's and Karen's, is of a ethereal beauty that is beyond the physical.