"Woman" in Swahili is "mwanamke", a compound of "mwana" (daughter) and "mke" (wife). So to get the plural, you combine the plurals of both components, "wana" (daughters) and "wake" (wives).
Why are all the images Caucasian people? They should be African people.
Most of mine are shown as Africans. I think they're picked randomly out of a selection of ethnicities each time you do a lesson.