I'm going to concur with the "try them on" sentiment.
One of the things about women's clothes... the sizes are MUCH less consistent than men's clothes. When you buy a male pant that has a 34 waist, you can probably buy it without even trying it on because all men's clothes of equal sizes are within about 5% of each-other. So if you know your measurements, you're good. Women's clothes... no. Sometimes I seriously wonder what some manufacturers are smoking. I've tried on size-16s that were like 2 inches too big, and others that I couldn't even zip up. In my present wardrobe, I have everything from sizes 14 to 18. And I have shirts ranging from Medium to 2XL that pretty much all fit the same. When I'm trying on shirts labeled "large," some of them will be WAY too small, some will fit perfectly, and others will be too big.
With women's clothes, it's really a crapshoot. The sizes are all over the place. You can use the charts to get a general idea, but the odds of anything in that same size fitting exactly alike, unless it's from the same manufacturer, is pretty much 0. To find clothes that actually fit, you're going to have to try them on and see for yourself. There really is no other way. Especially since we trans girls tend to have weird body proportions that take a bit of effort to fit well in women's clothes.