I'm sorry if I confused you simplify_my_life, On android devices, you can have different address books. On my phone, contacts are stored in the phone contact list, Google contact list, my email program and it looks like WAZE started having an address book. Android Lollipop has a new section on the contact entry called Connected via or something like that which shows which address book the contact is stored in. Verizon Cloud only backs up the phones address book. Although, I hear some people are starting to see Verizon Cloud backing up google contacts.
My experience with the cloud is that each phone number on my account has its own cloud. I have 5 phones and I only see my contacts so I'd be surprised and upset if the kids contacts came from a cross pollination of clouds. Emma's suggestion is one way they can show up in your cloud. Another way I can think of is if they are logging into the website with your userid instead of their phone number and making changes on the website.
Hope this helps clear up your mystery.
