Charlotte Brontë notoriously had two sides of her character. In a letter to Ellen Nussey: "At home you know I talk with ease - and am never shy - never weighed down by that miserable mauvaise honte which torments and constrains me elsewhere." This was about the time an Irish clergyman visited her father. Charlotte surprisingly got along well with him, and a few days later he wrote to her asking for her hand in marriage. Considered quite a silent, unfriendly character to the world, she was witty in her own home with her friends.
In The Professor, Frances Evans Henri seems to have multiple sides. With her pupils and Mdelle Reuter, she cannot hold her own - they torment and bully the shy young teacher. But with Crimsworth having her as a pet favourite, she grows plump and rosy, and becomes happy and confident. What's more, after they marry, she is a stern, respectable matron in the day with her pupils, a wild tender fairy with Crimsworth in the evenings. She teases him in French until he makes her read Wordsworth. (Seriously what kind of punishment is that?) She is submissive to her "master" Crimsworth, but argues vehemently with Hunsden, even using "hell" in her argument. Hunsden observes this with some amusement. It is because she loves Crimsworth and wants to be looked after him - she says no one else would ever marry her, and she would never love anyone else. But there is a willing slavery and unwilling slavery - the former with William, the latter with Mdelle Reuter and society in general. While she is petted by Crimsworth who adores her, she pets the despised pupils who have little money, and mollycoddles her own son. It is implied that Frances must switch personalities in order to survive in the world - not an easy thing, and something she never seems to have done before. It does not seem satisfactory to one's mental health, then on the other hand it illuminates the nature of Charlotte Brontë herself - she realised she could not show her true self to the world, but to be false all the time would constrain her. This is an interesting solution so to speak, because instead of the usual diligence, etc. there is also the theme of personality helping success - having a firm hand, for example. One cannot be true to oneself - not to the world.
Lucy Snowe in particular is susceptible to this. We think her as a bore, a secretive character, but she herself states that everyone has a different opinion of her, and only Paulina is right. She is not so "learned and blue" as Madame Beck would think; like her creator she has an instinctive delight for art rather than dry old books, she scarcely knows mathematics and languages, her accomplishments are few. It is raw instinct - some kind of genius I believe Charlotte thought she had. She is not as fiery as M. Paul would believe, being quiet in public though independent in silence. She is not as wise as M. de Bassompierre would have her, as precept and companion to his only child. Interestingly the people she mentions are those who respect her to some extent, not the ordinary teachers and pupils she deals with. These ordinary people I fancy would find her a bore and a strict hand, perhaps unfriendly and aloof. Ginvera likes to call her a crabby old creature. But the truth is perhaps a mixture of all these. There is no real Lucy-ness. She is a complex character. She puts on a lively front for the play in the fete, flirting with Ginevra like a man. Perhaps it is partly to ridicule men, but it also shows that she can only shine when she is someone else and not herself. Lucy lacks animal magnetism, that is her problem. Only as a "quiet inoffensive" creature, or "Madame Minerva Gravity" can she hope to please Graham and M. de Bassompierre. As a passionate person she arouses the wrath of M.Paul who accepts it later on. This is modern stuff - this state of not being who you are, the sort of thing that came later on in literature and pop culture. What a visionary Charlotte Brontë was!
Jane Eyre is Quakerlike and drabby to the world, fiery and passionate within. Being plain and uncharismatic she cannot get away with being passionate to the world. But the real double-sidedness brought out in Jane Eyre is Mrs Reed. Everyone thinks Mrs Reed is good, but Jane knows she is unkind. Mrs Reed treats people differently. She is nice to her equals because she likes them and it is only polite to do so. But Jane is a dependent, an orphan and not even pretty or charming, and therefore she oppressed the child. No doubt Mrs Reed is charitable in her own way to her local parish or whatever. But it is not a charity of the individual, it is a charity borne out of duty.
Even in Shirley you see this in Shirley Keeldar, charming and likeable to society in general, but herself a bit of a misanthrope. She dislikes seeing houseguests, especially the Wynnes. But she will go out to visit house-parties, probably at the Sykes', and urge the shyer Caroline to do so. Shirley likes gossip but she is not particularly close to anyone except Caroline. Her charming facade to the world is a mask for the visionary girl who thought of the First Bluestocking essay. Caroline is a more complex case. She has low self-esteem, something which cripples her from facing society, but she is not devoid of some affection. The rest may exclude her from their conversation, but Mr and Miss Hall love her as a daughter figure. I think there may have been part of the unworldly child in her, which commands affection from these quarters and from Shirley herself. Shirley at first befriends her because she thinks she needs looking after. (A bit like how Mrs Gaskell befriended Charlotte). Mr Yorke sees her as a "lass" who resembles his former love. Hortense is condescending to her in a nice way. What Robert thinks of her is less certain, but he is indulgent and in love with her. Part of Caroline's attraction to some people may be her childlike innocence, the sort of purity that Rochester sought in Jane Eyre. Caroline is very fond of Shirley but she does not take the initiative to seek her out at first because she is diffident "too English to get up a friendship at once." She seems aloof though she is burning with passion inside. This foreshadows a later time when Charlotte Brontë told her friend Mrs Gaskell she was too scared of loving Mrs Gaskell so much because she felt she couldn't be loved in return. And Charlotte knew that Mrs Gaskell's friendship was genuine. Only that she felt she could never be as important to her as she was to Charlotte. It is not dislike or indifference but strong liking that prevents Caroline from being too friendly to Shirley at first. She hates the idea of being repulsed by one she cares for, and subsequently humilitated. Even with Robert she is ashamed of showing him so much affection.