Transfer iPhone 4 to a different Apple ID

My daughter's iPhone 4 is currently registered to my own Apple ID; I've also installed a separate instance of iTunes under her Windows login on our shared PC, so she can have her own iTunes library. However, everything I download on my Apple devices is available on her iPhone, which is not ideal!

Q1 - if i create a new Apple ID for my daughter, can she register the iPhone to this new ID without losing all her apps, contacts, etc.?

Q2 - how can I update my daughter's iTunes instance to use this new ID and resync the original library contents?

Thanks for your help.