In a word — yes that will work. (Okay I am too
talky.)
However, from experience, if she is wanting to wean her friends away from emailing her using the AOL account simply changing the Reply-To address is unlikely to change their behavior or address books. Too few of her recipients will even notice the change.
The best strategy I have found, if the account supports an auto-reply, is to setup the auto-reply to say something like…
This email address is deprecated and will be turned off on December 31, 2013. Juliet Jone's preferred email address is jjones (at) icloud.com. Please note the change in your address book.
Then about September she can add this as a signature on replies to messages she receives on the AOL account.
If AOL does not support an auto-reply, sometimes called vacation mail, feature, she can create a rule in Apple Mail that will automatically reply to messages received on the AOL account. With all that it is almost guaranteed there will be the few who "do not get the message", "ignore the message", or blithely go on about their way and wonder why they lost contact.
