Where is this accent from?
Solution 1:
Her accent is one of a South African actress doing a generic (Midwestern) American accent. In other words, it is an approximation of sounding American, but not regional. It probably shifts slightly to the accent of the person with which she is in scene at the time.
My South African wife speaks with an American accent. Most Americans hear her accent as being close to their own enough for her to be American. Yet, far enough from their own accent for my wife to be from their region. She can sound to a Texan like another Texan. But, not like a Texan from the part of Texas the Texan is from. My wife’s accent will shift if she is talking to a New Yorker, Londoner, or Tamil. That is part of the curse of giving up your own accent for too long.
Another South African can tell that my wife is from SA almost immediately. Even though they may be thrown off or confused by my wife’s accent at first. However, they can not determine from which region of South Africa.
Her brother was only 9 years old when they moved to the States. He has more of a Metropolitan/big city Texas accent with a twing of a Midwestern rather than a twang of country. But, his accent does not shift. And, another South African would not recognize him as a fellow countryman through his accent.
Lesley-Ann Brandt moved to New Zealand around the age of 18. Her SA accent will be a little more persistent.