Texts, phone settings and photos can all follow easily. Just make sure you backup her Lumia 920 first (Settings > Backup > App List + Settings, and then there's Text Messages).
Then once you get the fabulous Lumia 1020, all of the settings will automatically apply, the texts will be recovered, and all of her apps and games will immediately start installing. Sadly, app + game data can't be restored. It's annoying, I wish we could use SkyDrive for that purpose (I've got 25GB free SkyDrive storage, grandfathered in, why can't I use it to save my games and apps data?!).
Mind you, I'm on a serious campaign about this with Microsoft. I haven't spoken to anyone high up enough to really make any difference, but I'm hoping my chance to chat with Panos Panay this Thursday night will be my chance to pass my idea on to someone high up at Microsoft, and hopefully make it happen. Sadly, he's not on the Windows Phone team, so I won't hold my breath, but I'm going to give it my best shot, that's for sure.