Greg responds...

The character of "Elisa Chavez" was created before Salli was cast. We had a
basic look for the character, but no final models. After Salli was cast, we
asked her what her ethnic background was. (African-American largely, but
also Native American.) That seemed like an interesting background for Elisa,
so we changed her name to "Maza" which means "iron" in the Navajo language
(or at least that's what I was told by my assistant). We gave Elisa an
African-American mother and a Native American father. Then we asked Salli if
we could give photographs of her to our character designers. She said yes,
and they adjusted our existing models to look a bit more like Salli. So her
"look" was inspirational rather than, say, "traced".

By the way, we obviously reused the Chavez name for Elisa's boss Maria.
Two other discarded Elisa last names that were reused are (Maggie) Reed and
(Matt) Bluestone.