My DD8 is 52-53" tall and weighs 74 pounds. She is certainly more trunk than legs, but I don't have a seated trunk measurement on her. She rides harnessed in a Britax Frontier 90. It has the click tight install. I noticed tonight that her shoulders are even with the harness again and went to move the headrest, and therefore the harness, up again. There are no more settings! She has the headrest and harness at the highest height and her shoulders are just even with the harness. I know on some other seats, there is a caveat to the "at or above shoulders" rule for harnesses once you reach the top position, but I don't see anything like that in our Frontier instruction manual. Does this sound right? Has she outgrown the harness by height?