I saw that post of the “I lost 30 lbs. and 10 sizes.” I’m not sure how that happens, but her body is doing the things it wants to–however, it is very unusual and none of us are going to come to any good comparing ourselves to her.
I’ve lost just over 20 lbs. and a bunch of my pants are getting loose enough that I need a belt now, but they still fit in other places. I’ve been measuring and based on that I’ve lost at least one size, but my clothes were snugger than I realized when I started. Now that I realize that I’m sort of horrified about wearing clothes that I was convincing myself fit, when they didn’t at all.
The other issue is that most women tend to carry weight in specific places–some women in their bellies, some their hips, some have big thighs, some are bustier. So you might just still be carrying weight in one of those places that’s keeping you from fitting into a smaller size.
In the end, since you don’t have measurements or photos, the only thing to do is to take both now, keep taking them and KCKO.