I admire her breathing. This song needs a lot of air and consistent muscular strength whilst holding the tune. Sorry for my funny expressions, I'm not an English native speaker. She's a good role model for any soprano rehearsing this song.
In memory of my beloved wife, Myungshin Kim, a good mother of two young daughters. You live in my heart now. I miss you dearly. Schwarzkopf was her late father's favorate singer.