I knew he'd say no. Why had I even asked? I stared at my hands—red, cracked, old woman's hands—and saw what was in store for me: a whole summer of drudgery and no money for it. Cooking, cleaning, washing, sewing, feeding chickens, slopping pigs, milking cows, churning cream, salting butter, making soap, plowing, planting, hoeing, weeding, harvesting, haying, threshing, canning—doing everything that fell on the eldest in a family of four girls, a dead mother, and a pissant brother who took off to drive boats on the Erie Canal and refused to come back and work the farm like he ought to.
I was yearning, and so I had more courage than was good for me. "Pa, they pay well," I said. "I thought I could keep back some of the money for myself and give the rest to you. I know you need it." (2.fractious.115-116)
Think about all the duties Mattie lists on the farm. Previously, her father has stated that he can't run the farm alone, and it becomes clear here that running a farm in the early twentieth century Adirondacks requires a ton of hard labor, long days, and self-sacrifice. Mattie is the only one who can help Pa as much as he needs it, and she's torn between her desire to do so and her desire to earn money to go to college.