The third room on the first floor of the eastern wing belongs to @Sigrid. Sigrid will initially attack any who enter her room, but this is just to gauge their strength. If she can defeat you easily she will toss you out of her room and tell you to return once you've become stronger. If you manage to reduce her to 30% of her hit points she will yield and improve her relationship to her as friendly. Sigrid cannot be killed in her own room. If a player continues to attack her after she yields she will regain all her lost hit points, she will go berserk, and all her attacks will be critical hits.
If you become friends with @Sigrid she will be open to a Warriors Wedding where you celebrate your bond by becoming one with each other and way too much liquor. You will have to spar with her at every visit and you cannot be defeated too easily or she will once again shut you out.