LULULEMON Sz 4? 6? Base Runner Black Gray Mini Check Pique Ruffle Shoulder Top

LULULEMON Base Runner Black Gray Mini Check Pique Ruffle Shoulder Top Women's top by LULULEMON. Size is missing, I cannot find a dot. Underarm measures 15 inches across or 30 around, unstretched. My mannequin is a size 6. I would guess this to be a 4, maybe a 2 or 6, but best guess would be 4. Gray mini check pique. Long sleeve, ruffle shoulder, pullover. Good condition, no stains, holes or pilling. Length -apx 24 inches shoulder to hem Bust -apx 30 around, unstretched Thanks for looking!