MISS MARPLE
Miss Marple has no backstory as such. She is an amateur detective, if she can be called a detective at all, she has never worked in any government agencies related to the investigation of crime. She can rather be described as a very attentive and wise woman who notices everything and not just notices, but remembers, analyses, and draws conclusions. Being a person who unravels mysteries, hidden motives and analyses people's behaviour is in her blood. Her "snoopy" nature also allows her to dig into their personal lives, sense unspoken communications and relationships between them (the secrets and affairs they are trying to hide), and from there, draw conclusions about their level of involvement in whatever crime she is currently investigating.
Miss Jane Marple, one of Agatha Christie's most famous characters, is portrayed as an old, frail and smiling old woman. She is described as a short woman with grey hair who always covers it with a hat or shawl: "Miss Marple is a white-haired old lady with a gentle, appealing manner". She predominantly wears a traditional old-fashioned dress and cardigan, emphasising her modesty and pleasantness.
Miss Marple is a highly social woman, very aware of what is and what is not appropriate in any given group, warm and outreaching to the community, and deeply interested in the problems of those around her. She takes a genuine interest in her family, friends, and neighbors: "Miss Marple always sees everything". Miss Marple has an almost universally tolerant disposition. She is mild-mannered and engaging, good-natured (and a little bit mischievous), and while she holds herself to certain standards, she isn’t above bending the rules a little bit, and hardly ever passes severe judgment on anyone. Instead, she listens to them in genuine kindness and with a forgiving nature and shows true remorse at their selfish or immoral behaviors. She doesn’t much mind the negative things various policemen say about her, but continues to go on about her business, unruffled and unconcerned by their disapproval.
Miss Marple's strength as an amateur detective lies in her keen intelligence, her extremely wide knowledge (especially when it comes to incidents in her home village) and, above all, her excellent knowledge of human nature, the study of which is Miss Marple's main interest, in her own words. She is equally interested in the disappearance of a pound of butter from the milkman's counter and a brutal murder; both are merely manifestations of certain human qualities. She believes that the characters and motives of people are always and everywhere the same, and, having correctly identified the types of actors, one can confidently draw conclusions.
Her main activities are knitting for her many grand-nephews, tending to the plants in her small garden and various community errands, which she does often and willingly (e.g. collecting donations for various local events). Periodically she gets out somewhere to visit acquaintances, relatives or just to relax. She always knits something, gives knitted items to acquaintances, relatives, or gives them to charity. Well versed in flowers, other plants and gardening in general. Very curious. In her village, where she has lived most of her life, she knows everything about everyone, is keenly interested in the life of her neighbours, always aware of all events, rumours and gossip.