I'm still confused about it. I have a feeling that she is in love with Kaneki, but it never states it. I know romance isn't really involved with Tokyo Ghoul, but I'm very curious.
I think she asked not for herself but for Touka instead. She saw Touka beeing pretty sad because of Kaneki and concluded that she may be fallen in love with him so she asked someone to understand Toukas feelings so she can help/understand her better, at least thats how I see it.
Edit (second question): I dont think Touka has/had a crush on Nishiki because she obviously likes Kaneki in a romatic way.