Finicky (adjective) – extremely or excessively particular, exacting, or meticulous in taste or standards

https://www.merriam-webster.com/dictionary/finicky

“In the certainty of his goodness, his righteousness, his holiness, Helga somehow overcame her first disgust at the odor of sweat and stale garments. She was even able to be unaware of it. Herself, Helga had come to look upon as a finicky, showy thing of unnecessary prejudices and fripperies.” (271-272 online version)

Understanding this meaning tells us that Helga was able to focus on exactly what she wanted to focus on which was the admiration of the man and was able to block out the disgusting smell of sweat and stale clothes.