> Born to and raised by Australian mother
I really don't think most people care about the fact she has an Australian mother. In fact, I myself had forgotten that fact. If she hadn't, I don't think it would really make a difference to how she is viewed in Australia. (My mother was born in Scotland but calling myself “Scottish” feels weird, like the real Scots are going to call me out for being a fake one.)
Virginia Roberts Giuffre has been called an "Australian" by the Australian media (e.g. [0]) even though as far as I am aware she has no Australian ancestry. She is also married to an Australian man but I think you are putting more emphasis on that fact than what counts. Most Australians, if they think of her as an Australian, it is because she has adopted this country as her homeland through immigration, not because she married an Australian. If she married an Australian but stayed in the US, nobody would think of her as Australian. If she had moved here as a single person, or with a non-Australian husband, people probably still would.
In somewhat of the reverse, the British politician Patricia Hewitt was born in Australia and grew up here, but I'd probably think of her as British first and Australian very much second. The country in which she has lived the bulk of her adult life, and in which she has had her political career, is more significant in identifying her than where she was born and raised.
[0] https://www.watoday.com.au/national/western-australia/virgin...