The ideal thing would be if she could set the Alarm notification only for text messages from the hospital operator, where she gets essentially all her pages.
Having a blanket Alarm for all text messages (little chats from people) would not do.
And limited reminder beeps (without jailbreaking) sounds pretty bad.
I'm not sure this will work for her. Seems like the right software (probably has to be by Apple) could solve this though.