Better put, that question should be, Who has the authority to mind the kids, particularly when the parents or guardian are out of town or otherwise very much indisposed, for a short period? In Utah and many other states, the answer is the person who holds a power of attorney specifically delegating temporary authority over the minor child or children. In Utah, that period can be no longer than six months:
A parent or a guardian of a minor or incapacitated person, by a properly-executed power of attorney, may delegate to another person, for a period not exceeding six months, any of the parent’s or guardian’s powers regarding care, custody, or property of the minor child or ward . . . UCA §75-5-103 (and no, I didn’t put the hyphen between properly and executed)
This temporary power of attorney is a nifty little tool that could come in handy for the babysitter or the nanny if the minor child needs to see a doctor or must have permission to do something at school, and the parents are (way) out of town or out of touch. And it’s a pretty simple document, at least the form on the Utah Court’s website is. (I wish I could say Wyoming allows such a delegation of authority, but I’m not sure yet. When I know, I’ll report back.)
My wife and I have one for three of our grandchildren and will have for the rest of them soon. Of course, we’re trustworthy and have a track record with minor children. So should the person(s) you grant such authority to. As handy as the temporary power of attorney is, it is not something to give away willy nilly.