I saw a bit of that, was very surprised by how lovely she looked. Yes thin, but not painfully so. She really ought to stop pouting though, it's that mouth action which makes her look less pretty than she actually is. For some reason, it also looks a bit brainless. I can't think why, but it's unfortunate.
But tbh this size thing is something I'm a bit sceptical about. Twenty years ago I was a size 8, and most of my clothes were too big for me (I was tiny) but I wasn't underweight or even particularly thin - just normally slim). I am now size 8 again, not because I am not at least 6 inches fatter all over, but because they have changed all the sizes and made them bigger. At the same time, they have actually started catering for women who are smaller than what used to be the smallest size, so they've invented what sounds like ludicrously small sizes. But when you realise that size 8 is actually nearer to what a 12 or 14 was twenty years ago, size 4 doesn't sound quite as small, does it? - It's just the equivalent of slightly smaller than size 8 used to be.
I've just looked at Boden's size charts and in my late teens I would have been a size 8 working on those.
I had a 24-25in waist but in Miss Selfridge back then I used to be a huge 12-14 which made me feel really fat (and I was slim, albeit bottom heavy mostly being a 1980s 'size 12' top and 'size 14' bottom then). I weighed less than 9stone and was/am 5' 8"-9".
I agree Caligula, I am a size 8 in some lines now but I got some old trousers out the other day (from when skinny jeans were in last time round ) and I couldn't get into the size 10s that I used to fit into. I am larger now than I was then, but take a smaller size because they have changed all the measurements.
I saw that programme and thought she came across brilliantly, I thought she was funny, took the mickey out of herself and seamed at total ease with life. Have to say I didn't even notice what kind of weight she was so it couldn't have been that bad.