Can I update an email address on my icloud account

Question

My current Icloud (apple ID) is being used by my child for their ipod touch with my email address.  I now have a new Iphone for both her and for my wife.  I think they each need their own icloud (apple id)!?!  So, can I change the existing icloud (apple id) to my childs email address and set her phone up to sync with it allowing my wife to use the existing icloud (apple id) with her new phone?
If so, are those Icloud (apple ID) then set up on the phones under settings...Icloud...Icloud account information area?
It may be obvious that I am a new "I" device user!
I failed to mention that I'd need to set up a new Icloud (apple ID) for my child.

Answer 1

Ok.  First, you don't have to use the same Apple ID for purchasing from the iTunes and App stores as you do for other services such as iCloud, iMessage, etc.  Everyone can still share the existing ID in Settings>iTunes & App Stores without creating any issues.  This will prevent any issues relating to accessing your purchased music.  They should, however, use separate iCloud accounts with separate IDs for iCloud, as well as iMessage and FaceTime.
You will first want to migrate your daughter to her own iCloud account with her own ID (again, she can keep the existing ID for purchasing).  To do this, assuming she already has data in the existing iCloud account, she will want to set up the existing account on her phone to download the data from iCloud.  This can be done during the setup process if her phone is not set up yet.  After doing this, go to Settings>iCloud and tap Delete Account.  (This will only delete the account from her device, not from iCloud.)  When prompted about what to do with the iCloud data, choose Keep on My iPhone.  Then set up a new iCloud account on her phone with a new ID.  If she doesn't have one, tap Get Free Apple ID at the bottom to create one.  After setting up the new account, she can turn on iCloud data syncing, and when prompted, choose Merge to upload the data on her phone to the new account.  After confirming that her data migrated to the new account successfully you can now set up your wife's phone.
If the existing iCloud account contains your daughter's data, you will probably want to go to icloud.com on your computer and manually delete it before setting this account up on your wife's phone.  If you don't, when she syncs with the account, her data will be merged with the existing data from your daughter and you'll still have to manually remove the daughter's data from the account.  Be sure your daughter's data is in her own account before deleting it from the original account or it will be lost.
Once the original iCloud account is free of your daughter's data, you can set up this account on your wife's phone, turn on iCloud data syncing, and when prompted, choose Merge to upload your wife's data to the original account.
Finally, to avoid getting each other's text messages or FaceTime calls, everyone should also have separate IDs for these services.  If they don't, for iMessage go to Settings>Messages>Send & Receive, tap the ID, sign out, then sigh back in with a separate ID.  For FaceTime, do the same thing in Settings>FaceTime.