I'm An Opportunistic Princess In-Charge of Solving Things

I'm An Opportunistic Princess In-Charge of Solving Things summary:

Princess Octavia was a high school girl until she was reincarnated into her beloved BL novel's world.<br>The fact that she's able to see her brother, the main character, and his lover so closely is a good thing, but both of them are male.<br>If so, won't there be trouble with future heirs?!<br>There's no way they'll make her take a political marriage to offer them a child, right?!<br>I don't want to be a character who's taken advantage of like that! If this is how it would be, I will surely find my own partner to be happy.....!!!