Not but what she bears with Mattie wonderful.
Logic? In ENGLISH?
I guess it just needs to be accepted as vernacular and older English to boot.
She bears with Mattie wonderful is clear now, no?
Correct English would say wonderfully.
Not but what refers back to the previous mention of Zeena having been a cranky...ie irritable...woman and forward to the face that Zeena DOES run out of patience with Mattie sometimes.
"She was always cranky, but notwithstanding that, she puts up with Mattie's sourness wonderfully but sometimes her patience wears thin and she and Mattie fight with each other, which upsets Ethan terribly" is probably the best rendering of the passageI can give you.