Also how the past kings have equal power in each generation because the FL's family are always supporting them. So when the condition of marrying the FL was to have the support of other nobles besides her family came in.
My guess is that if she only has her family's support, their would be other families who wants their kids to be crown princess and would be dissatisfied. There would be alot of bullying and assassination. For the FL she's lucky because she has the protection of the prince and somehow unintentionally helped others and gained reputation. Now this fake FL came up and did all those, boom she got arrested + her dad.

sorry but can someone explain to me the "anonymous" topic they were talking about. i can't quite understand it. thank you!