Basically my children have apple id's but no purchase power they use my apple is on their phones I can not link them to family sharing I have their phones on find iphone but thats it?
You say that 'my children have apple ids' and 'they use my apple id' - are they using their own accounts or your account for the stores (Settings > iTunes & App Store) ?
If they have their own accounts (which they are using for the stores) then what happens when you try to invite them into family sharing (Set up Family Sharing - Apple Support) ?
Does each family member have to have an apple id already established to be part of family sharing?
