Just Zipporah and her sons – almost all commentaries.
Also Yitro's wife and Yitro's sons – Minchah Belulah.
What was the relationship between the Jewish people and the Keinites?
Family ties
The Keinites were part of the Jewish nation – R"E HaModai in Mekhilta DeRabbi Yishmael Yitro Amalek 2, Targum Pseudo-Jonathan 18:27, Rashi 18:27, Ramban 18:1.
There was a political treaty between the two nations – R. D"Z Hoffmann Shemot 18:12, Fensham.