Need to turn off iMessage for an iPhone that no longer works

Question

My daughter broke her iPhone and the motherboard is fried. We got her an Android as a temporary phone until she is due for an upgrade in a few months. The problem is that when we try to text her on the new Andriod, on our iPhones (and any other iPhone that tries to text her) it still sends as an iMessage. Therefore she cannot receive any texts from us unless we turn off our iMessage (which causes us not to be able to receive other iMessages of course!). We went to the Sprint store, and they told us that we would need to turn off the iCloud for her phone, since Apple is recognizing it as still on and associated with her number. I cannot figure out how to do that since we can't access the phone settings. She is traveling this week alone with other family and I really need to be able to text her! She is 12. I appreciate any help.
This is an iPhone 4, with Sprint. We have 3 other iPhones, an iPod 4 and an iPad 2 on the same Apple ID account. We don't use the Cloud storage but I think the iCloud on the phone was turned on for a few things like Calendar.
Thank you in advance.

Answer 1

Support profile is here:
https://daw.apple.com/cgi-bin/WebObjects/DSAuthWeb.woa/wa/classicLogin?appIdKey= 58ef9db8ff4d201409e7270a68e4408ae1678e1618204c476572a1b5e5fb3518&path&language=U S-EN
She would have had to register the phone using her Apple ID/password.
Changing her Apple ID password is the only other way to fix this if you don't have access to the phone.
You can also "try" calling AppleCare.