Thanks everyone for the suggestions! Love the parachute one! The cills are big enough for her to sit on alright, but I worry about her being distracted by an insect or a bird or something like that and just instinctively launching herself at it. She is quite playful. Maybe I'll just put more insect screens up? 2 birds with one stone. She'd probably find a way through or to open it, but it might be enough to limit her interest.