If you had to name the villains of The Boxcar Children, these are the two. Fortunately, they only appear at the very beginning of the story, though. After the baker's wife reluctantly offers the kids a place to sleep, Henry and Jessie overhear her diabolical plan to put the older kids to work and send Benny to a Children's Home. (This is basically an orphanage, more or less.) The baker and his wife don't seem very interested in helping the children so much as themselves. When the baker's wife says, "I'll keep the three older children. They can help me" (1.40), we can see the extent to which she's concerned about her own needs over those of the orphans.
In any case, the children aren't on board with this plan at all. They flee into the night, and the baker and his wife are in hot pursuit—but not because they care, as evidenced by the limits they set on their search. Perhaps they feel a sense of obligation—they want to be do-gooders, but they don't want to necessarily go to the trouble of doing good. Quoth the baker's wife, "I do not want to find them anyway. I don't like children, but we must try a little while longer" (2.36). Luckily, that's the last we hear of her and her husband.