I had purchased this capri in size 8-10 a couple of years ago, and it was already a bit large. Lost some weight in the last few months (why is 2018 so damn stressful?) and size 4-6 fits better but is still quite large for its supposed size. Don't expect a tight fit, but you're likely to find it a worthwhile purchase too considering its purpose and cost.
Quick update: I should also mention that this is good quality workmanship. Not the kind of clothing that lasts you just one summer.
Quick update #2: It shrank after being washed and dried. Success, it fits perfectly now.