@Adhayra I'm pretty sure that Winter's family (and possibly even some of the servants under instruction of Winter's family) are manipulating both Violet and Winter. I think that anything Winter sends to Violet disappears and doesn't reach her, and since he doesn't communicate with her, she doesn't know that he buys her all sorts of things. Violet thinks that Winter could have a possible lover and that the dresses are for the lover, but they were actually meant for her all along and she just didn't know about it. In general, I think Winter's family is doing everything they can to keep the both of them under their thumbs. They want to keep benefitting from Winter's wealth, and they want to torment Violet, who was supposed to be their gateway to even greater wealth and social standing.
As for Violet's family, I believe that they relinquished their position as the rulers of the nation so that they could 1) shift the blame and responsibilities of the emperor's actions, and 2) avoid being under the influence of Winter and his family. If they had given him the title that he wanted because they were indebted to him, Winter would have held great sway over the country as a sort of savior who kept the commoners from starving after helping the royal family pay off their debts. This was definitely a political move on the royal family's part, but Violet didn't know anything about the stunt her brother was pulling.