Final answer:
Canadian female citizens over 21 gained the right to vote federally in May 1918, with women of color and Aboriginal women gaining full enfranchisement later, in the late 1940s and 1960s.
Step-by-step explanation:
Most Canadian female citizens over 21 were granted the right to vote in federal elections in May 1918, as per the legislation titled 'An Act to Confer the Electoral Franchise on Women'. However, it is essential to note that this legislation initially did not include all women, particularly women of color and Aboriginal women. It wasn't until the late 1940s and 1960s that the enfranchisement was extended to include these groups fully. Canadian women's contributions during World War I and the work of suffragists were pivotal in achieving this milestone.