Please give me at least one source to read, Chris Talk. Otherwise, it's not clear to me that there is another wife besides Tzipporah.
Goodness, Google has hundreds of sources.
Very quickly I have just been skimming
http://www.ot-studies.com/Documents/did_moses_marry_a_cushite.htm Looks like that quickly gives the story, I had forgotten her name, Tharbis, but it is beginning to come back to me. Moses had been a great general of Egypt in his 30's or so and the Exodus did not take place till he was in his eighties.