How do is set up family share while having multiple devices under one current apple id? We have three iphone 5's, one for me the dad, and two for the kids. each phone was set up under my apple id. I want the ask to buy function set up.

We have three iphone 5s in family, one for dad, two for kids. All were set up under one apple id. Up to now, when kids make a purchase or download an app on their phone, it also comes on my phone.

I would like to:

1- set up the ask to but feature that is on family sharing - so I can control purchase, but also do not have to download on my phone if I do not want to.

2- right now one phone gets backed up to icloud, one gets backed up to iTunes and one does not get backed up.

Any suggestions would be appreciated.