Who are Don and Eva? Reread previous pages to locate the answer if you can't infer from the above section. Why would Tessie request that they "take their chance "?

From the text, we can infer that Eva is Mr. Hutchinson's daughter, that she no longer draws with the Hutchinson family because as a married woman, she no longer qualifies. Don may also be Mr. Hutchinson's son, possibly they have another mother, and Mr. Hutchinson was a widower when he married Tess.