49% is probably fine, though if you can drop it a little more by moving the water dish or other simple efforts, you might do that. Too moist an environment (as it understand it) makes it more likely that the blisters can pop and provide an opportunity for further infection. I hope Rusty, Caren, Becky, or someone else with medical experience will jump in and correct me if that is wrong. You will still need for Shelby to be hydrated enough to build a full fluid layer between the layers of skin for her to have a full, successful shed, so 70% or so for shed should be good.