Well, first of all, Ma Baxter is fat. Really, really overweight. Like, obese. How do we know this? And why on earth do we keep dwelling on it? Because the narrator does. Every time you turn around, there's a mention of how big she is:
Okay, okay, enough with the fat-shaming. Is there a point to all this? Well, maybe.
Poor Ora Baxter. Not only is she isolated out in the middle of a forest with just her husband and son, but she's even left alone for days at a time while they go hunting or trading. The family has barely scraped by for the past 20 years, without even have a well near the house—she has to go out to a sink-hole to do the laundry, for Pete's sake. As Penny says, "(T)wenty years is too long to ask any woman to do her washin' on a seepage hillside" (9.58). (We couldn't even make it a few months with our laundry in the basement.)
Add on to that the fact that she's had baby after baby, who have all died as infants: "The babies were frail, and almost as fast as they came, they sickened and died" (2.20). Most of them weren't miscarriages or even stillbirths, which are already tragic enough, but babies born healthy, who made their mark on her heart, and then died when they were a few months old. Can you blame her for getting a little grumpy? Just listen to her talk about it:
Sorrer strikes the same all over. Hit makes a different kind o' mark in different places. Seems to me, times, hit ain't done nothin' to you but sharpen your tongue. […] Seems like bein' hard is the only way I kin stand it. (17.177-179)
In other words, Ora closed herself off to feelings, took a pessimistic view of life, and, we think ate to comfort herself. What else could she do? Long bubble baths were out, and so was retail therapy. She had no other women to talk to, and no phone, TV, or Internet. She immersed herself in the details of keeping food on the table—that's all she had.
One other thing: "Ora" sounds a lot like a form of the Latin word for "mouth" (think "oral hygiene). And Ma really is all mouth: she's either scolding or eating.
When little Jody was born, Ma Baxter had already decided she wasn't going to love another kid. Instead of loving him even more because of all his dead siblings, she treats him almost like one of the animals: "'You and them hounds and all the rest o' the stock,' she said. 'Mighty lovin' on a empty belly and me with a dish in my hand'" (3.5). Nice, ma.
The only time she ever shows any approval or real kindness to Jody is when she helps him build the pen for Flag. It's completely out of character for her to do manual labor like this, so she has to explain why she's moved to help him: "I never figgered you had it in you to work this-a-way" (31.84). She's proud of his new maturity (defined by ability to work hard).
This moment actually gives us a little hope for her. Maybe, as Jody grows up and takes on more responsibility, Ma Baxter's life will get just a little easier—and maybe she'll eventually grow easier to live with.