I've got an iPhone 3GS jailbroken which I used and had synced with my iTunes library. I've now got an upgrade to an iPhone 4s so I've given my 3GS to my Mum. She has plugged the iPhone into her iTunes and she has synced some apps, but when she goes to sync some music this message pops up:
Is it safe to click erase and sync baring in mind this is a jailbroken phone or will it erase the jailbreak and take off Cydia etc...?

Is it safe to click erase and sync baring in mind this is a jailbroken phone or will it erase the jailbreak and take off Cydia etc...?