You can move over now, and she can move over later.
#1. Her e-Mail address will not go away.
#2. At the end of June 2012, she will still have her e-Mail address, but she will not be able to access the actuall e-Mail themselves via the older MobileMe system.
#3. If she wants to use her e-Mail address for the purposes of sending and receiving mail, then she will have to move over to iCloud.
I hope that is more clear.
Blessing for Thanksgiving.
Your daughter is fearing something that shouldn’tbe feared btw.
Regardless, Her e-Mail address is her Apple ID and that will not go away.
Her Mac's mail program (mail.app) will still function for any (or multiple) mail systems that she chooses to use. MobileMe is a mail system. And iCloud is also a mail system.
Currently, November 2011, both of these system are up and fuctional at the same time, yet independent.
After the end of June 2012, the MobileMe e-Mail system will be unavailable.
So, after the end of June 2012, she can choose to either go with the iCloud e-Mail system or do something else. Her e-Mail address will be hers after June 2012 regardless, but the MobileMe e-Mail servers that make the routing and intermediate storage of mail possible will be unavailable.
Remember, there are two different concepts to grasp.
#1: One is the mail program that resides on her hardware. This will fuction as it is forever.
#2: The other is the mail routing system(s.)
Her mail address is:
A: an Apple ID.
B: an e-Mail address.
The e-Mail adress (B) has to communicate with some e-Mail routing system (#2). Currently that system for her is MobileMe, in the future it will need to be iCloud.
Ps: Just to clarify further iCloud is many things.
• It is an e-Mail routing system.
• It is many other things.
As an e-Mail system it is stand alone and will work with most modern IMAP supporting e-Mail programs.
As to the many other services that it provides in general you need more recent programs to access those features. For the most part, those more recent programs reside with Lion.