Although we don't know much about Yasuko Namba as a person, the brief glimpses we do get reveal a focused, determined, and courageous woman.
Here's what we do know. Before her attempt on Everest, Yasuko had already ascended six of the Seven Summits, which are the tallest mountains on each of the seven continents. Everest, of course, is her grand finale. You wouldn't expect such impressive feats from this "demure and reserved […] forty-seven-year-old," but the truth is that these "her sparrowlike proportions disguised a formidable resolve" (1.17). You go, girl.
And then, of course, there is Yasuko's unfortunate end. Instead of dwelling on the details, however (many of which are impossible to know), we think it's much more fulfilling to look at the exceptional way that she lived, achieving greatness despite others' preconceptions of what she could do.