1) Because he always want to put his half brother (oliver) in trouble to get his father's wealth.
2) Because she make a deal with rose and Mr brown law to tell them any new news about Oliver and monks& Fagin bad plans to Oliver which lead to killing of her on hand of bill sikes.
3) He always sympathetic to him because he was alone and hopeless that he was looking for him father's money to get the right of it back to him and searching for his family too , and at end he adapted him as his kid.
4) because when he was walking with the couch with rose he saw the orphanage and ask rose that they can help them and teach read and write words and get a cloth for them and make their life be better.
5) she walks slowly like a spy without making any noise to Eavesdrops monks and Fagin's talking because she feel that something bad will going to be planned between them.
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Good Luck For You And Me