Cotton On V-neck T-shirt White with black stripes

Cotton On Women's V-neck T-shirt, White with black stripes and black trim around the neck. The white of this T-shirt has little black fibres through it. This t-shirt's label is actually printed on the inside of the back of the shirt! In my experience, the labels which are printed on to the material, they don't last very long. They can easily wash off within 2-3 wears and washes! Although, there are certainly some that last much longer. However, the label which was printed on to this t-shirt has almost completely washed off! I don't know for certain what size this top is, however, I do know that when I bought this top, I would have been wearing a size 10 or 12 in a t-shirt. This mannequin is a size 8-10 and this Tee, although it is a relaxed fit, is very loose on her. So, I'm thinking that this Tee should be a size 12, or possibly a 14, But just in case I am wrong, here are some measurements, Underarm to Underarm- 55cm Waistline 58cm length 70cm.