The term "calico bonnet" does not have a single, universally accepted definition. However, it most likely refers to a bonnet made from calico fabric.
What We Can Infer
Calico: A plain-woven cotton fabric, durable and affordable, often with simple patterns.
Bonnet: A head covering worn by women, covering the head and ears. It can be simple and practical or elaborate and decorative.
Therefore, a calico bonnet would likely be a simple, practical head covering made from calico fabric, probably worn for everyday use by women in the past.
Possibilities
A type of sunbonnet: A utilitarian head covering for sun protection during outdoor work.
A 19th-century bonnet: Calico was commonly used for clothing during this era, making a calico bonnet practical and affordable.
A regional or cultural tradition: Some areas may have had specific traditions involving calico bonnets.
Without further context, it is difficult to pinpoint the exact meaning of "calico bonnet."