Here are some quotes from Z for Zachariah:
"I just realized that, after all this, I still do not even know his name" (Chapter 5, pg. 53.) She's talking about the fact that she's gone to extreme pains to save this man's life and she doesn't even know who he is really. She's just glad that now she's not alone.
"As I walk, I search the horizon for a trace of green. I am hopeful" (Chapter 26, pg. 249.) This quote is at the end she she's determined that she has to leave her safe little valley. After Mr. Loomis makes it unsafe, and she's had to do some things that she doesn't want to have to face each day, she is headed for the horizon.