My story takes place in the futuristic world of 3000, when everyone thinks it's the apocalypse. By this time in human society, the world has changed pretty drastically. Children have virtually no value anymore, until they turn 18 and enter adulthood. There are two main types of families: the traditional families and the regular families. The traditional families are expected to have between 4 and 9 children. The Regular families *supposedly* are childless. Some of these families have one child that they hide away in closets or basements until adulthood. So by the time May rolls around, there are supposedly no people still of the new country that combines Sweden, Italy, and the USA. Except the kids that were left behind. One of my main characters is one of those kids, stuck in the city streets of the US. She was meant to be the first child of a traditional family, but her father died in a freak accident when she was six. From that day on she lived the life of an illegal, in a walk-in-closet. She is now ten years old. she is very defensive, and tries to make it on her own even if it's very illogical. She also trusts no one with secrets or any details of her past. She is constantly looking around as if she is trying to catch someone watching her. She is also a very quiet character. I'm not sure how to develop her: through dialogue, no, she's too quiet. Through past experience, no, she's lived in a closet for the past 4 years. please help!
Through the narration of the story. Giving a running visual of her actions, expressions, thoughts, body language and everything else it takes to tell the story and develop her as a character.
Well, if she's been cooped up for the past four years, ever since she was six, she's bound to have little to no social skills. She may make mistakes like act rude when she genuinely doesn't know it's rude (like speak out of turn, or yell out 'HEY' at a superior, that kind of thing.) When people respond harshly, it may give her even more of a reason to not want to interact with them. She might try to push away people who want to help her, because she doesn't understand them, or she thinks they have some ulterior motives. Just some thoughts.
I don't know... To me the whole thing you said sounds a bit all over the place and not very well thought out. Firstly, one country comprising of Italy, USA and what was it? Sweden? What kind of country is that? Spread out, disjointed, weird yet specific mix of cultures, on first glance it makes absolutely no sense. If you want to throw things together like this, there should be a really good reason and logic behind it. Then, children are of no value. How come? It is unnatural that children, who are the principal motivation as they continue life and the species, should be of no consequence. Psychologically it makes no sense unless, again, there's a really good, solid logic behind it. Such as some kind of war (just an example) so children are bread to fight and parents distance themselves from them in order not to suffer too much when they die. Families are supposed to have no children but they have them anyway and then lock them in the cupboard. Why? If they are afraid of getting caught, they must want those kids desperately, in which case they will make sure they spend lots of time with them, showing that they love them, in which case the kids won't be lost and unsocialised at all. If not, then why are the adults so sadistic as to go out of their way just to terrorise their children by locking them in wardrobes? It takes effort and a good reason to do something like that. There are so many motives that could potentially be interesting, but they need to be recognised and mentioned or implied somehow. Then, you'll have all sorts of clear ways in which to characterise your main character, because she will epitomise the whole situation in one way or another. At least, that's how I'd go about it.
Just an idea that may not work for you, but you could try to develop her character from the point of view of what she hears from other people's narrative and how she feels about it. "Do you want another slice of pie?", her mother asked, and [character's name] felt the offer tinged as always with the reluctant acceptance that more precious resources would need to be wasted on a liability such as herself.
I agree with jazzabel. I don't think this idea is very well thought out, for the reasons she said. But if you want to carry on with it, you can consider the option of having your character keep a diary. That's a pretty obvious way to allow you to develop a solitary character. Show the reader excerpts from her diary and she'll become a living character.
I'm with Jazzabel as well, there are a lot of questions raised that you just may not have included. (I would like to point out, that previously, children were thought of as property in the US. If you go back through the history of Social work, you find out that our child protective laws were originally our animal protection laws. Go figure. Of course, nothing like ours today, but children were generally seen as property. Also, if you check into sociologist studies of third world countries and all that, families tend to have a large amount of children for the fact of almost lottery, at least one will survive and be willing to take care of the parents when they're older.) In general, superpshyco has got my general idea. You said she was one of the main characters? What perspective are you writing this in? Delve into her head as well, grow her through her thoughts and ideas and feelings.
Many stories deal with characters who are shy, socially awkward and severely sheltered. Some of these are non-fiction books which would be a great place for you to begin your character development work (like Natascha Kampusch's book about her 8 year captivity as a child.) In terms of dialogue, some of the greatest books ever written have very little dialogue and manage to convey their ideas and character development that way. You have to get into your character's head and find their voice. What is her motivation, what are her fears, what does she like, why does she do the things she does?