“Note: We are expressly told in Exodus 2:21 that Moses was given for his wife, Zipporah, the daughter of Reuel (aka. Jethro) the Midianite, the priest of Midian. We are not expressly told that he married anyone else. It is possible for Zipporah to be of Cushite/Ethiopian ancestry if Reuel’s wife was an Ethiopian, or even the mind-staggering possibility that Abraham’s 3rd wife Keturah was an Ethiopian. (His 2nd wife Hagar was an Egyptian.)”

(from “The Cushitic wife of Moses” in Wikipedia’s List of names for the biblical nameless.)