There are several elements to doing outstandingly good work on a thesis project. These include the quality of your research, the quality of your arguments, and the quality of your writing. To take the simplest first, you should always edit very carefully for grammar, word usage, and spelling as most English teachers are reluctant to give passing, much less good, grades for error-strewn prose.
Next, in terms of argument, you need an actual thesis or claim about orphans in the Victorian period, not just a general subject area. What is it you have to say about orphans? You could, for example, argue about whether the portrayal of orphans in these texts was realistic or sentimental, or you could look at how religion (especially Evangelical Christianity) affected the treatment of orphans, or you think about how class and gender affected the experiences or portraits of orphans in these works. The narrower you can make your focus or claim, the easier it will be to research and support.
Finally, a thesis needs to position itself in relationship to existing scholarship. There has been a significant amount published on this topic, and as well as reading your primary texts, you should research the topic in the MLA International Bibliography and look over previous scholarship on the topic.
The key to a successful thesis, and yours sounds very interesting, is clarity, explanation and connection. Obviously you need to be very clear in your thesis statement regarding orphan life for these four strongly motivated characters. You have chosen your orphans well, although you need to be able to devote equal amounts of time, analysis and connection between all four characters. This is, as correctly stated above, a popular topic. Try to read previous theses, and develop an original idea of where you want to drive this paper. You don't want to tread grudgingly down familiar territory, because you want to ultimately impress your reader that you are taking these orphans on a new adventure so to speak. While tackling the traditional notions of Victorian injustice regarding the orphan experience, try to delve into some commonalities, perhaps psychologically speaking, of Pip, Jane, and the others that pulls them together despite the harsh historical times. Think of what these characters share that places them on some similar road to either redemption or damnation, depending on your chosen perspective, as both topics can be proven nicely either way.