You know that school boards do not have HR managers, right?
I would call their bluff and walk her to class anyway.
Yes I thought that this was a bit weird too. Also that even if this was an HR Manager (of the school board, of the teachers, whatever), making a call like this is in no HR Manager job description I've ever heard of. (And yes, I have heard of HR Managers overstepping their bounds, but never in any scenario even remotely resembling this one).
OP are you absolutely sure it was an HR Manager associated with the school or board that made this call?
(And to some of the others posting here, I don't think OP was told to stop walking her daughter to school - nobody can prohibit that, and certainly not a possibly-faux HR Manager, I think OP was told to stop walking her daughter to class - which I took to mean OP cannot go into the school with her daughter, she must leave her daughter at the school door.)
School DISTRICTS may have an HR manager. School BOARDS do not.
You also really need to get rid of this idea that all school district employees are hired by the school board. For a brief time I worked as a substitute teacher. I was not hired by the school board. I was hired by the principal. It is simply not true that all school hirings, in all districts throughout the country, are all made by the school board.
Isn't that a matter of semantics? The BOE is the district in most cases.