IPhone restored as another iPhone

Ok, so I tried to download some pics from iTunes to my mums iPhone. I haven't plugged it into iTunes before so when I tried it said 'Would you like to set up as new iPhone or restore as old iPhone'. I didn't know what that meant to I clicked on restore. Now, my mum's iPhone has restored as MY IPHONE! It also lost all the pics on hers. I just need to know if there's any way of undoing this.

If you did a backup of your mums phone, you can do restore backup and select the last backup made (date and time included in the backups name). I think your mom will loose her apps but all her things like contacts, notes, messages, pictures will be back.