Your Abstract Conclusion will be a vague representation of what your early research leads you to believe you will conclude. For example, (purely hypothetical made-up example) if your research leads you to conclude that in the three Austen novels, those who have sense and practice self-restraint are the ones who are the most unhappy and unfulfilled, then your Abstract would discuss your Thesis Conclusion in terms of your findings and their meaning, something like this: I found that in Austen's three novels those who practice sense and self-restraint suffer by watching others achieve dreams while they sit by and their own dreams fade through misunderstandings and an inadequacy of interpersonal connection. Therefore Austen is stressing that sense and self-restraint can be as severely limiting as sensibility is. [Remember, I'm making this example up, it's not based on research.]
Another made-up example might be that you find that in Austen's novels at some point characters with sense who practice self-restraint must throw it off in order to fulfill their dreams. Your Abstract might address the resultant contents of your Thesis Conclusion in a manner similar to the above hypothetical suggestion.
You could conclude that sense and self-restraint are themes that appear in all three of the novels in terms of how each of the female characters have to subject themselves to society and expectations that go beyond their own expectations, and how they have all had to sacrifice their happiness, liberties, dignities, and peace of mind in order to please their mothers, society, and the world as they know it.
The sense of self in all these women is inimitable. They all represent independent thinkers, or dependent romantics. They are easy to define characters, and their characteristics are very clear. Their self restraint comes from the fact that those characteristics which make them all so unique have all been put at risk due to the cruel expectations of the social strata to which they belong, and this is what caused their ultimate sacrifices.
The best conclusions have two elements.
1. Conclusions should not add new information. If one does this, this will leave the reader with that new thought, rather than the whole argument. So, resist getting too fancy.
2. Conclusion should, instead, summarize and reassert why your thesis was a good one. Also it should emphasize why your supporting arguments deserve merit. In this sense, your conclusion should harken back to you introduction. So, if your thesis is on restraint, you could write something like:
"In light of the above discussion on restraint, one can conclude that Austen weaves the theme of restraint in the following ways..."