And there is also Miss Valentine. She was also able to fly, though without wings and she isn't even a logia. But as Robin has a limited time to use her wings, maybe she can't remain weightless in the long run? I think we'll see more of these abilities later on.
Miss Valentine couldn't exactly fly, persay, she could simply make herself weigh a single kilogram (which is actually still pretty heavy). Think of it like a dandelion seed or something; she can float around for a long time, but she slowly falls due to gravity, as opposed to Bird Logias who can legitimately 'fly'.