Hi yes wider is the extended family, ones beyond those that live with the child/ren/immediate parents and siblings. Caring & social networks take into account the situations for adopted children, children in permanent or temporary care, friends and mentor networks.
The importance is the significance that input from others has on and for the child - physically and emotionally. Their contribution to ensuring a child's well-being and welfare is what makes aiming for outstandingly reaslistic outcomes for children possible.
Why famillies are important - family learning argument
Contact a family
states ' What parents do is more important than who parents are.' pg 1. Where contact & interaction is given & provided by others it could be considered that the same principle applies.
Here's a quote from page 4 of the AQA Home economics book for child development
The extended family is one where other close members of the family - very often grandparents, aunts, uncles, cousins, etc. - live with the family, or close by.