Day trip from Miami -Advice needed

I will join my husband on a business trip to Miami the week of March 17 (Spring break🙄) . I’d like to take a day trip to either Bimini, Key Largo, or Islamorada. I will be by myself and would like to relax on a beach, possibly shop, and go to a cute restaurant with a view. Which would be the best place to visit that week ? TIA