Andy is colourblind.
It's not that she literally can't see any colours, but that her colour discrimination is much worse than most people. She genuinely can't tell a cerulean sweater from a turqouise sweater, and that's why she has a hard time taking fashion seriously. Even in the outfit montage, she's dressing mostly in shades of grey, black and white. She might not even know that she's colourblind, and just assume everyone is making meaningless distinctions.
Emily is anorexic.
The characters in the film engage in crash dieting a lot, but when people go on crash diets its a short term thing, usually to compensate for eg holiday weight or before a big event like prom or a wedding. Emily is always doing it. She also has signs of anxiety (understandable when you work for Miranda) which is common with anorexic people. She also gets sick constantly which is what happens when youre anorexic.
Miranda used a surrogate for the twins.
It's clear they're her
daughters and they seem to be around 13. Miranda is presumably in her late 50s or early 60s making a pregnancy near impossible when they were born. Especially since she's in the fashion industry where gaining any kind of weight is heavily