It could also say 'will become the most South Asian woman ever to...', doesn't mean that she has only now become South Asian.
'highest-ranking woman ever to serve in government' just makes it sound like her 'high-ranking' is independent of her serving in government to me. Especially given that it's a bigger more general milestone than the preceding sentences.
'highest-ranking woman ever to serve in government' just makes it sound like her 'high-ranking' is independent of her serving in government to me. Especially given that it's a bigger more general milestone than the preceding sentences.