What is the meaning of parsimony in paragraph 1?

Della has to be thrifty to make her small amount of money last. Parsimony makes her cheeks burn. She’s not happy (Happiness) about it, but neither does she show the tradesmen that she’s overly emotional (Emotional). You can’t substitute the word generosity (Generosity) for parsimony: you can’t be broke and generous, at least not with money.