Fifteen and a Half Inches
She has a mobility disability.
She was, on the facts of that autumn, unable to reliably get from a maths classroom to a cafeteria in the time allowed, and had missed meals.
That is not a hardship.
That is, in the language of the statute, a denial of access to a programme or activity, and it engages Section 504 of the Rehabilitation Act, and the school district has an affirmative legal obligation to address it on notice, and a parent can trigger the process with an email.
Not a lawyer.