Topic, then a small sentence about it: Cô ấy tóc dài

To describe someone by one feature, name the person, then the feature, then the adjective: Chị Lan tóc dài. Lan has long hair (literally, Lan, hair long). There's no "has" and no "her". The person is what you're talking about, and tóc dài is a small sentence about them.

This is how people describe looks and character: mắt to (big eyes), tính nóng (quick-tempered): Ông ngoại tôi tính hơi nóng. It works for places and things too, and it's the language of food reviews: Quán này đồ ăn ngon, giá rẻ. This place has good food and low prices.

Aches go the same way: Dạo này em hay đau lưng. My back often hurts lately. With illness, bị often comes in front: Em bị đau đầu.

The longer form with có also exists, Chị Lan có mái tóc dài, but it sounds like a written description. To contrast two people, add thì after each: Chị Lan thì tóc dài, còn chị Hoa thì tóc ngắn.