Chanel sweater

Chanel sweater, size medium, but is very small. 100% cashmere extra button on the inside . tag says medium, so that is what I put for sizing, but it really does not fit like a medium. I don’t know what a size 4 or six would feel like but I wear a size 8 and this is very short and definitely not a medium. this was my mother’s sweater so it is vintage. I wish I could keep it, but it just doesn’t fit!