iPhone 6s-What to do???

Complicated (or, a good challenge for someone out there): My wife has a new iPhone 6s 32GB Verizon. She previously had an iPhone 4s, which we occasionally backed up on my MacBook Pro via iTunes. The 4s DIED recently. Would not power on, would not be restored...nothing...dead. She got the new 6s and immediately started using it, including entering a lot (60 or so) of new phone numbers and email addresses related to a bus trip she was organizing. She also took a lot of pictures on the trip. So now we hook it up to the MacBook pro and iTunes gives us the choice of "Start New" or "Restore from previous iPhone 4s." Will either of these options allow the CURRENT data on her phone to remain, or will they both scrub it clean? We need to begin backing up via iTunes or iCloud, but she doesn't want to lose her new data. Is this a legitimate dilemma, or can we go ahead and choose one of the options?