Hate to break it to you, but her being from another country doesn't matter. She legit straight up is the one doing most of the work and running the country. The King does almost jack shit. She perpetuates the shit status quo, and in fact encourages the nation's absolutely braindead decision to weaken the outer nobles and leave them all basically in poverty and with a hatred of the central power and the royalty, and with basically no military to actually do their job of protecting the border.
The Main issue is the fact she is from the other country matters, the kingdom is ruled by the King and not the Queen, Second The Army that watch the border are under the power of the Dukes and Marquis not the outer nobles for that goal was implemented the system for the outer nobles to have no way of rasing a huge army while the Core Nobles have the army and the Territories bordering Enemy states (the fact is the 3 of the 5 idiots families are in charge with the protection of the border), 3rd The System is brain dead but this is not unnotice by the Royal Family both the king and the Queen wants to get rip off it but guess what they have to deal with others Core Nobles that wants to keep the System up, Like the Maquis that wanted to kill leon, Hell Even thanks to Julius Breaking his engagement with angelica, the royal family lost their Backing with the Redgrave Family even making their position more unstable and later turning the Redgrave into the main rivals of the Royals now that the Marquis is dead.
The Royals have a plans to deal change the system but everything backfire, thanks to Olivia in the Original Timeline (
in fact was the Vengenful spirit of the first saint that took over Olivia's body) and thanks to Marie in the current one, Leon's actions have been a Blessing for the royal family for their plans was to change the system in a couple of years but thanks to Leon they can Change it instantly because he pretty much destroyed every opposition