She shares an itunes account with her kid for parental control reasons. The calander and contacts merged to both phones... I don't understand why it downloaded her calandar to her kids phone and uploaded her kids contacts to her phone.
It sounds like the contacts and calendars may have merged because both her and the kids phones are signed into the same iCloud account. It will merge the information on the phone with the iCloud account when you sign in. She can still use the same Apple ID for purchasing apps and music but use a different Apple ID for syncing contacts and calendars with iCloud. She can even turn iCloud syncing off for contacts and calendars, or log out of iCloud completely without it affecting her purchased music or apps. You can update these settings in Settings>iCloud.
the cameras doesn't zoom any more
I believe in the earlier versions of the iOS, you would have a bar that you could slide to zoom in. In iOS 6, you can just pinch or move your fingers apart to zoom in or out. Kinda like when you are trying to zoom in with Safari or a picture that is in the Camera Roll.
she gets her kids friends facetime msgs.
She will need to update the Apple ID signed in for Facetime. You can check this at Settings>Facetime. If she is getting their iMessages as well, she might want to check the settings for that too under Settings>Messages.
Also all of the songs are listed for re-download in Itunes on the phone but the ring tones she bought are not there as well as what she uploaded from CD's. I am guessing that the songs from CD's are either on the old hard drive or stored on the new computer when we did the back up. Would the ringtones be there as well?
The CDs and ringtones should be in her iTunes library from the old computer. You can find steps to transfer information from the old computer to the new computer using this article: http://support.apple.com/kb/ht4527
If she doesn't have access to the old computer, she can contact the iTunes Store to see if they will regrant the ringtones to be downloaded: http://www.apple.com/support/itunes/contact/
Basically it sounds like the main issue is that she shares and Apple ID with her kids for purchases. She can still do this, but she will want to log out of that Apple ID in the iCloud, FaceTime, and Messages settings on either her or the kids' phone so that they don't share those things.
I hope that helps!