、。
She isn't a beauty by any means, but she has an indescribable charm.
Literal
She [topic-は] never beauty is-not [but-が], indescribable charm [subject-が] exists.
A classic Japanese personality compliment that follows the けっして~ないが~がある template: deny the obvious surface trait, then assert a deeper, harder-to-name quality. 何とも言えない ('cannot be put into words, indescribable') is a fixed phrase that combines 何とも ('in any way at all') with the negative potential 言えない ('cannot say'). 愛嬌 (also written 愛敬 as in this sentence) is a culturally rich word: not glamour or sex appeal, but warm-hearted approachable charm — the openness and friendliness that draws people in. It's the kind of trait Japanese descriptions of personality often prize over photogenic looks, especially in popular figures like comedians, idols, or politicians.