You can in fact go topless on the beach, but not the pools, and you can wear what ever type of bottoms you would like on the beach or pool. Or you can go over to the Au Naturel part of the beach and wear nothing at all.
You are and you can show her as it's answered in the FAQs. But keep in mind, the beach at CN has a public walkway at the water's edge, so it's up to her on her comfort level. In other words, people from other resorts, adults and children can walk the beach at the water's edge as well as the locals and vendors.
is allowed in designated beach areas: Couples Tower Isle: End of the pier off the main beach.
Couples Negril: Main beach.
Couples Swept Away: Main beach.
Couples Sans Souci: Main beach.