Not sure how old your D is... but from 7th grade to 8th grade my D gained 100 points on the critical reading section of the SAT with no preparation. I assume they covered what she needed in school, and she likes to read. She also gained something like 60 points on the math, but she did a small amount (2 hours?) of prep for that. So it is definitely possible, even without a lot of prep, depending on her age and what they are learning in school that year.