Maeve, thanks for writing this. As one of those children raised in poverty who had a mother that made sure that I had a language-rich environment, I was academically prepared for college. My test scores were good. I had absolutely no idea about how challenging it would be, and I dropped out. I finally finished at age 42 and went on to work with students who were having trouble in school. A college education can be attained, but some of us have to take different paths.
You are so right about starting the preparation with preschoolers. A kid who only has a can of corn to read at home has a difficult time becoming proficient in reading.