She's bitter, sarcastic and sadistic, especially towards her servants and maids. She loves being in control, which drives her want for being the next head of the Cromwell family through the roof. If something isn't done her way, she doesn't get frustrated or angry she simply punishes or removes the 'problem'. If Rose is in a good mood she generally acts a bit nicer to her servants and maids. Typically she always gets along with her sister, Teacake without a problem.
Rose only carries around an old sword(still in tact) for protection, showing off or just for threatening maids, servants or just pesky visitors.
As a child, Rose was always spoiled rotten and loved expensive things. Never did she actually care for them, so when they broke, to her it didn't matter at all because by that age she believed everything can be fixed with money. As she got older she remained the same and the problem even got worse as Rose believed everything was expendable, one of the reasons she was kicked out of the kingdom by the Queen and King along with her sister, Teacake.