She married for political reason but also because the old poppa proposed to her and would only help her country if she agrees to it, a conditional international union, pretty much to establish stronger nation stance to have a easier time dealing with foreign invasion and internal conflicts with help from the bigger nation(e.g. almost got raped in early chapters by her own subordinates). In early chapters right before the marriage in a church I believe, she said she has to maintain the dignity of a queen, hence she can only give the prota her first kiss and has to reserve the virginity to the king from the other kingdom because of the tradition of noble marriage.(the old poppa has a daughter that is only few yrs younger than this knight queen). In this chapter she's inviting prota to her bedroom, so at this point by the semantic way she straight talks about this kind of topic compared to holding back and innocent at the church, it's safe to assume that she already had sex with the old poppa right after the marriage giving out the first time,(it's also been quite some time likely over a month since the marriage, it'd be strange if they didn't have it considering the king was after her in the first place) hence no longer cares and invite the prota to her bedroom. The princess (old poppa's daughter) is likely to take over the authority and handle nation affairs together with the small nation's knight queen right now.