In what way does Mrs. White have power over her husband in the early parts of this chapter?

Mrs. White seems to be able to pressure her husband using emotion. While Mr. White is content with one wish, she wants more,

She came stumbling across the room toward him. "I want it," she said quietly. "You've not destroyed it?"

Mrs. White is assertive and demanding. Mr. White seems incapable of countering her demands,

"No," she cried, triumphantly; "we'll have one more. Go down and get it quickly, and wish our boy alive again."

The man sat up in bed and flung the bedclothes from his quaking limbs. "Good God, you are mad!" he cried aghast.

"Get it," she panted; "get it quickly, and wish---- Oh, my boy, my boy!"