Q: I have taken a sim card from one iPhone and placed it in another.  What do I have to do next to the phone with the replaced sim card?  The screen and apps are from the old phone..

Does she have a backup via iTunes or iCloud of her old phone before it died? If so, the following has instructions. Transfer content from an iPhone, iPad, or iPod touch to a new device - Apple Support

Note that since the phone is already set up (i.e., not new, the first step will be to follow the instructions below from the bottom of that link.

To transfer a backup to a device you've already set up, you need to erase the device: Tap Settings > General > Reset > Erase All Content and Settings. This will erase any data that's currently on your device. After you've erased it, your device will restart and you'll see the "Hello" screen. Now you can transfer a backup to your device.