Final answer:
Australia has yet to have a black female Senator. Canada and the United States have had female and black senators respectively, while the UK's legislative structure does not have senators.
Step-by-step explanation:
The question is which country has yet to have a black female Senator. While the United States has had black senators, such as Roland Burris, and black female Representatives like Shirley Chisholm, all other countries listed have had women in the Senate but not specifically a black female senator. That being said, Canada elected its first female senator, Cairine Reay Wilson, in 1930, long after the Prime Minister was petitioned to amend the necessary act to allow women into the Senate.
Australia has also had female senators but none that identify as black. The United Kingdom does not have senators but rather lords and ladies within the House of Lords; while they have had black and female Lords, the combination of a black female in this upper chamber is scarce and not analogous to the concept of a Senator. Therefore, by process of elimination and considering the information given, Australia has yet to have a black female Senator.