What is the Reasonable and Prudent Parenting Standard?

So there is a buzzword going around in the social welfare system - Reasonable and Prudent Parenting Standard - also known as RPPS.  It basically means that foster parents should use their common sense when making decisions for their foster children.  But what is the legal definition?

It has its origins in the "Preventing Sex Trafficking and Strengthening Families Act"  of 2014:

Sec 111  SUPPORTING NORMALCY FOR CHILDREN IN FOSTER CARE

(a) Reasonable and Prudent Parent Standard.—

(3)  Technical assistance.— The Secretary of Health and Human Services shall provide assistance to the States on best practices for devising strategies to assist foster parents in applying a reasonable and prudent parent standard in a manner that protects child safety, while also allowing children to experience normal and beneficial activities, including methods for appropriately considering the concerns of the biological parents of a child in decisions related to participation of the child in activities (with the understanding that those concerns should not necessarily determine the participation of the child in any activity).

From 42 USC § 675(10): 

(10) (A) The term “reasonable and prudent parent standard” means the standard characterized by careful and sensible parental decisions that maintain the health, safety, and best interests of a child while at the same time encouraging the emotional and developmental growth of the child, that a caregiver shall use when determining whether to allow a child in foster care under the responsibility of the State to participate in extracurricular, enrichment, cultural, and social activities. (B) For purposes of subparagraph (A), the term “caregiver” means a foster parent with whom a child in foster care has been placed or a designated official for a child care institution in which a child in foster care has been placed.

It is also referenced in 42 USC 671(10):

(B)that the standards established pursuant to subparagraph (A) shall be applied by the State to any foster family home or child care institution receiving funds under this part or part B and shall require, as a condition of each contract entered into by a child care institution to provide foster care, the presence on-site of at least 1 official who, with respect to any child placed at the child care institution, is designated to be the caregiver who is authorized to apply the reasonable and prudent parent standard to decisions involving the participation of the child in age or developmentally-appropriate activities, and who is provided with training in how to use and apply the reasonable and prudent parent standard in the same manner as prospective foster parents are provided the training pursuant to paragraph (24);

(C)that the standards established pursuant to subparagraph (A) shall include policies related to the liability of foster parents and private entities under contract by the State involving the application of the reasonable and prudent parent standard, to ensure appropriate liability for caregivers when a child participates in an approved activity and the caregiver approving the activity acts in accordance with the reasonable and prudent parent standard

This all seems kind of vague.  How is it applied?  It comes up when there is a decision to be made for the foster child.  Who makes the decision - do you need to go to court and get a judge to sign an order, or do you have to ask the caseworker, or do you have to ask the biological parent, or do you ask the child?  It depends on the type of decision.  But for most decisions, the foster parent can decide.  

But what is the actual standard?  I haven't found the legal definition of the standard (but I will keep looking), but each state welfare system provides its own definition.  Here is a typical one:

The reasonable and prudent parent standard asks caregivers to make decisions for youth just as they would for their own children. It is characterized by careful and sensible decisions that maintain the health, safety, and best interest of the child, while also encouraging growth through participation in age and developmentally appropriate activities.  (Source: https://www.nj.gov/dcf/about/divisions/dcpp/rpps_pg.html)

So it basically delegates to the foster parent the decision making authority based on the "best interest of the child", which is another vague buzzword.

This raises an interesting question - what if the foster child challenges the foster parent's decision?  How would they do so, could they contact the caseworker and complain or could they get an attorney (a guardian ad litem) and go to court and ask the judge to decide?