Dells got the money by trying to save some here and there. She negotiated prices when buying food, to try to get it for cheaper, “until one’s cheeks burned with the silent parsimony that such close dealing implied”. Parsimony means being very frugal.
O. Henry wrote, “life is made up of sobs, sniffles, and smiles,” meaning that life is either very bad (sobs), very good (smiles), or somewhere in the middle (sniffles). Della is in a situation where she feels defeated and can’t fix things in time. When O. Henry says, “with sniffles predominating” it means that life is mostly full of disappointment.
