Jonnie Robinson, Curator, English accents and dialects, British Library Sound Archive, writes:
Jamaican patois is a fascinating insight into the way languages emerge and evolve when people from different cultures come into contact. The history of the arrival in the Caribbean of large numbers of people, particularly from West Africa, is well documented and created a situation where a number of new pidgin languages developed. A pidgin language is a linguistically simplified means of communication that emerges naturally when speakers of two or more languages need to understand each other. Initially the speakers who worked the colonial plantations would have spoken a variety of ethnic languages, but the language imposed on them would, of course, have been English. Amongst themselves, however, a pidgin language would have been used, based on the sounds, vocabulary and grammatical structures of all the contributing languages.
Crucially a pidgin language is not a mother tongue. This means it has no native speakers, but if the pidgin remains the principle means of communication within a community for a sufficient length of time - as, for example, on the plantations of the Caribbean, then it becomes the first language of children within the community. At this point it begins to increase in linguistic complexity as it's spoken in a wider range of contexts and adapts to serve the purposes of a fully fledged language. This is referred to by linguists as a creole - a language that has expanded in structure and vocabulary and has all the characteristics of other languages, including exhibiting social and regional variation, hence the differences between, say, Jamaican patois and Trinbagonian patois and the fact that we can define one speaker as using a broader variety of patois than another. Crucially, however, this creole generally competes with a related language that has more prestige within the community and so it has an ambivalent status even among its own speakers. Throughout the Caribbean, for instance, Standard English, albeit a Caribbean version, is the language of education, although Jamaicans are rightly proud of their patois as an important expression of their cultural identity.
The lack of the verb to be in the statement she breeding, where Standard English would normally require she's breeding is typical of the type of structure that occurs in a Creole. The meaning is clear despite the simplification, as is the case with the statements she have breed again and her breed again. The first of these statements uses the verb to have unmarked for person and in both cases the word breed is unmarked for tense. In Standard English the statements would most likely be rendered she has bred again or she bred again, although arguably even the word breed belongs more to Jamaican patois than to contemporary British English. The use of the non-standard subject pronoun her is in fact also possible in a number of English dialects - particularly in the West Midlands and West Country, which shows how seemingly distinct and geographically remote dialects often share the same features. Finally the word pickney used here or piccaninny is intriguing as it's known to exist in several pidgin and creole languages across the world. It's thought to originate from the Portuguese word pequeno, meaning small, and perhaps illustrates the role played by Portuguese sailors and merchants in the early trade routes down the West African coast.