Yes, it should work fine. She'll want to use Google for her calendar, contacts and Google Voice for voicemail. If she isn't syncing with Google now, she can go into the Contacts and Calendar in OS X Mountain Lion and choose to sync with her Google account.
The biggest difference is iTunes, and she won't be able to sync that with Android. There is a great program called DoubleTwist, though, that she'll put on both her desktop and her phone. That will work just like iTunes. There are a few things she won't be able to do, for instance iTunes Match won't work with an Android phone. But she can use Amazon or Google for music, and it will work great.