@shinketsu Metric system is shit because you can't split things evenly in quarters, eights, sixteenth or thirty-secondth. Sure, an inch is 2.5cm, but what's a quarter of 3 cm?
My wife's 5'1". She does the same thing Amano does at random times. She's not an athlete nor competitive. It's probably related to people wishing for something they don't have.
If I had to guess I'd say 5'9 - 5'11 (175 cm - 180cm). Assuming Megumi is about 25 centimeters shorter that would put her around 4'11 - 5'1 (150 cm - 155 cm)