Since the whole family knew that Arianna was engaged to Maxim and that the two were head over heels with each other, no one tried to separate them but simply put more restrictions on Arianna so that she wont meet Maxim all the time.
Marylyn was simply afraid that her daughter might give her a grandchild before she graduated. Wouldn't their family be mocked for that?
Arianna had achieved a lot of things during the past three years and the family was very proud of all that. Now that the little girl was older and her twenty first birthday was celebrated in such an extravagant way; how could they stop her from having her own fun?
So, when Arianna told her mother that she was going to Ark Continent, they knew that it was impossible to stop her. They have done their best already and if they continued, they may anger not only Arianna but Maxim himself.
