Hum, let the girls decide when they get there. They're big enough to take it off and put it back on when they are done using it. Aren't they? Lena could help too. Three young healthy people to lift a fiberglass lid should be plenty. Then you can watch them all play, relax, chat and take pics. If the sunroom has a window you can join in or pretend to be asleep and eavesdrop. You can learn a lot like that. That's what my grandma would have done. She had to be where the action was but she never got too far from her A/C for too long.