J Jill women's tank top Size S

vibrantly colored J Jill tank. Fabric is slightly stretchy. Rayon Lycra spandex blend. Very soft and flowy. measures about 18" across by 23" long. Good used condition. Only worn a few times. I am a size medium and this fits me. I can't tell if the tag says size S or 3. This was bought a few years ago and I'm unsure of their sizing back then.