Write out your research question in its broadest form:
What other questions would you need to answer?
Now, how do you use these questions to generate search terms? Identify the main nouns in each of your subquestions and use AND and OR to combine them in various ways
Think about synonyms for those terms. For example, what other names was she known by? La Chingada, Dona Marina, Marina, Malintzin, others?
Literature, Mythology, Religion
Don't forget to search in Academic Search Complete - it's a great multidisciplinary database and might provide some perspectives you hadn't even considered.