SPI schoolbag costs 3xx is okay as it can be used for three years(P3-P6). I think schoolbag for P1-P2 should fit the kid's , no need to buy so expensive or big . And also I get the information that spinal cord distortion(eg S-shape-most common) is not much related to the schoolbag , but it is congenital. Remember to check your daughter's condition esp. when she is 9-13. Girl to boy ratio to get the illness is 9 to 1.