Does Mrs. Baker actually hate Holling's guts in The Wednesday Wars?
Mrs. Baker is a good woman who does not hate Holling's guts. It is true that she is irritated with the situation that makes her responsible for Holling every Wednesday afternoon, as is evidenced by her attempt to have him repeat sixth-grade math during that time instead of remaining in her classroom. Her initial reluctance to have to essentially babysit Holling is understandable - there is no curriculum to which she can refer to fill in the time, and, more significantly, her husband is being sent to fight in Vietnam, creating a great upheaval in their lives. Mrs. Baker's veiled reluctance at having Holling to deal with every Wednesday actually has little to do with Holling himself; it is the situation which is the source of her frustration.
After a month of having Holling do odd jobs around the classroom on Wednesdays, Mrs. Baker, being the resourceful teacher that she is, decides not to waste the opportunity at hand and begins to read Shakespeare with him. As the two tackle Shakespeare's plays, she begins to know Holling better, and becomes extraordinarily sensitive to his needs. She saves the day by driving him to Yankee Stadium when his father lets him down, and shows him a new way of looking at his community by taking him on an architectural tour.
I think that it would be fair to say that while Mrs. Baker did not really know Holling at the beginning of the book, she most definitely did not hate his guts. There was nothing personal in her discomfiture with the situation that caused her the extra work of being responsible for him on Wednesday afternoons. Once she got better acquainted with him, I think she liked and respected him quite a lot.