Why did Anthony Horowitz give Rose as my characters new name?

While deciding why Rose replacements name is what it is I did research in to the symbolism of roses. The first thing I can upon was that the flower expresses promise, hope and a new beginning. So I believe the reason why the institute gave her the name Rose was to give her a fresh so that she could start again and try and become a better person. The flower also expressing hope that may be what Rose as a character has in order for her to be able to get through her time in there that one day she will be forgiven and forgotten so she can leave and have her life back which is far from what she will ever have. The other symboles of the Rose is its thrones and these symbolies defense, loss and thoughtlessness. Rose I believe was also given her name because of how she suffered loss of her life outside of the institute and lose of the little girl Natty that she looked after. She also has a lot of defense within her characteristic because when it is mentioned about different items that I believe she used to kill Natty she get up tight and defends herself claiming that they are not hers. Rose can also be defensive when it comes to her talking about the rule book that she always refers to when anyone breaks a rule. She was also thoughtless in the acts that she took part in for her to end up being in prison.