Thanks everyone! My DD is approx 51 inches at the moment but hard to know what she will be when we go. We have done the "smaller" coasters/ thrill rides at DW: ie. not space mountain, not the Tower of Terror, not Rockin Rollercoaster, not Expedition Everest. I would be happy to do Space Mountain at least once but didn't know how my DD would react when she was so little and having to sit separate etc. Of course, now my husband is making noises (he'd love to come I know, just don't know if we can work it timing-wise): if he comes, we would still have the upside rule though (which is mostly because my DD is very underweight and I don't know how much of the height requirements are also about width).
We went to DW at the end of August and loved it. DH is an Aussie so we are used to going there and both he and my DD love the heat (and hate the cold). I'm the least heat tolerant of the three of us and I did fine. It was so quiet and empty. Of course, if we went in November, we might be escaping the cold, so.... We would be going around August 27th or so, or November 3rd. We'd love to go for my DD's bday but it's pretty much right at Thanksgiving and we don't want that.