[basilray]

It shouldn't be too hard. I picked up a Diamond for fun a week ago. Added it online w/o issue and everything was service (voice and data) were both running in less than 5 minutes.

Go to Sprint.com and sign-in. On your My Sprint page that shows your phones, click the link for Activate a New Phone. It will ask for the ESN you want to switch to...and BAM! Done and Done.

Some 3rd party retailers might even sell her the phone but add it to your line. I had a friend who wanted the Pre and went to Best Buy. They sold the phone to his father's phone line on the same account, but activated it to my buddy's line right away. So that may be an option as well.