Trying a new XXS brand - Rachel Roy (30% off + free ship)

I've been eying the Rachel Rachel Roy collection for a while now ever since discovering that they offer size XXS. I went to Macy's to check out the fit, but of course there were no XXS or even XS's! Thanks again to Chloe, I just found out that Friends & Family is going on right now at Rachel Roy with 30% off (no code needed) plus free shipping for purchases $75 +. Perfect excuse for me to try out this brand.

Since I have no idea how this line fits, I'm going to stay away from pants and jackets. It's not a petite line, so most items may require a hem or shortening of sleeves. Here's what's in my cart:

1. Striped Fitted Cotton Skirt in XXS. 19" long. Only $24.49 after two rounds of discounts. I expect this skirt to be much longer and less fitted on me than on the model. I'm hoping to make it work appropriate with a blazer.

2. Elastic gathered-waist skirt in XXS. 18.5" length - perfect for me. I first saw this linked on 9to5chic and have been interested in it ever since.

3. Antique gold necklace, on double sale for $25.89. I've been looking for a bolder piece like this to brighten up my solid-colored dresses.

4. Twisted double layer dress in XXS. Colorful 100% silk and lined - not bad at all for $70! I have no occasion to wear this, so I'm going to pass on this item.

Returns are only by mail, for a $7.50 flat rate (but I'm probably going to return via USPS first class for less $, if needs be). Do any petite ladies have experience on sizing with this brand?

PS - Also get 2.5% cash back on Rachel Roy with ebates!