Cup size scales differ so much from store to store after getting past the 'normal' sizes that saying "ZZZ" doesn't mean much without some qualifying numbers. If following the official UK scale it would mean the difference between her bust and under-bust is 50"... but at that kind of size where exactly do you measure them (bust measurement is meant to be across the nipple, but when they are that big the nipples are probably lower on the chest than the under-bust is)
Not certain if there is an official U.S scale, but I think past DD they almost follow the alphabet in terms of the number of cup sizes (as opposed to the UK which goes , FF, G, GG etc), even if they have a few different names, so I believe the difference in this woman's bust and under-bust could be as low as 31"
