I wish she actually put the guards on blast, and didn't just whine behind the back. I seem to recall she said something to their face, which made them ashamed, in the WN.
Unfortunately for you guys, I pretty sure she's a love interest, she obviously gets a crush on MC.
That said, I haven't read all the WN, and there's the adventurer girl who loves him as well as some of her partners who seem to love him as well, so it would be silly to have the daughter be his lover unless this goes the harem route. Let's be honest though, Japan loves the cliche of the daughter ending up as the partner, unfortunately.