Bonney is a slim woman (despite the enormous amount of food she's capable of eating), with long pink hair and purple eyes. She can also appear as a small child due to her Devil Fruit power: in this form, she has similar, although obviously more childish, facial features, and isn't as tall nor as buxom as in her adult form.
Her outfit consists of a white low-cut tank top that exposes both her midriff and cleavage, along with a pair of orange-and-black striped buckled shorts with long, thin suspenders. She also wears black high-heeled boots which reach up to her calves, with large laces coming from the openings, and a pair of hot pink and dark red stockings with a yellow sun-like motif on them (a pattern seen other times in the One Piece world). The hat she wears is a green Furażerka with a light-green lining. She has an anti-eyebrow below her right eye, bright red lipstick on her lips, and is sometimes seen wearing a brown furred jacket.
In an SBS section, Oda drew the Supernovas as children. Bonney is shown with shoulder-length hair as opposed to her current back-length hair and a rounder face. Her clothes and face are somewhat dirty.
In Oda's depiction of the Supernovas post-timeskip, Bonney is shown wearing a black hat (possibly a sunhat similar to Usopp's, judging by the rim) with a brown furred coat or cloak. She also uses pink lipstick as opposed to red one.