The passage below comes from Emily's runaway imagination by Beverly Cleary.
Then one Sunday, when the store was closed and no one had banged on the door to get Grandpa to open up, Grandpa and Grandma drove over to the farm in the new Ford. Grandma was wearing her good serge suit and her best hat. She had a resigned do-or-die look on her gentle face.
I'd like to ask the meaning of 'a resigned do-or-die look.' It's not easy to figure out the meaning of the part in question because the two word resigned and do-or-die seems to contradict in meaning each other. Resigned means that grandma yield to grandpa's insistence to go on driving with his descendants. But the meaning for do-or-die in the dictionary says it means 'very determined'. So I cannot draw how the grandma looks in my mind.