On the one hand you are absolutely correct about these accommodations being for the benefit of the children

On the other hand, if your employer is denying your reasonable request for PTO, or denying accommodations in an emergency unrelated to children, then your company is already understaffed.

Any employer that can't handle the sudden absence of an employee is failing at management and is not somewhere I would want to continue working. If your shift needs everyone to show up or things fall apart, run for the hills.