I haven’t read these articles, so I can’t exactly tell you what to write but here are some suggestions I can give you.
-Take notes on the major differences and similarities of how the author presents the topics of crossing the border / immigration in her editorial and biography.
-As seen in the prompt, it states the central ideas in her writings are about these topics, so that should be the basis for your thesis.
-You should state in some way how similar and different the biography and editorial are in presenting the ideas (immigration/border crossing)
-I don’t know how long you’re essay is supposed to be, but you could break up the essay into two parts: two paragraphs about similarities and two about the differences. You should also do a introduction and conclusion paragraph.
Again, these are just suggestions, I don’t know exactly what these writings are about.
Once you plan out what you’re going to write about, it gets a lot easier. Best of luck.