Final answer:
The girl's shoes have gone unpolished since spring due to other tasks or priorities that have taken precedence.
Step-by-step explanation:
The girl's shoes have gone unpolished since spring because she has been busy performing other tasks or has not placed importance on polishing her shoes.
In the first reference, the girl was focused on washing her feet and knees to prepare for a trip to Baltimore, so she did not have time to polish her shoes. In the second reference, the girl had dirty hands, a hot and sticky face, and uncomfortable boots, which likely distracted her from polishing her shoes.
Lastly, in the fourth reference, the girl had her hair ruined at the barber and sought to get her dress cleaned, indicating that she may have had other priorities besides shoe polishing.