I think, one good thing the writers are doing with this show is they are not changing the characteristics of the characters overnight, even though we might feel they are not being themselves in one particular scene, they immediately pull us back to the true nature of that character. For instance, Amber Sharma has come a long way with this understanding with Guneet and has evolved as a person, but there is still that part of him who speaks without realizing he has hurt the other person just in the case where he says to Guneet that she is right she is not a mother so she wouldn't understand.
Nia's character is of 24 year old, who is confused between friendship and love and it natural for a person of that age. We have all matured through our experiences, yet there is that element where she cares for her dad and that is her core while she wants the freedom to do her own thing, she still wants to be a part of her dad's world. The writers have shown her maturity initially in the show when she wouldn't cross the line with Randeep. The similar kind of an understanding in her characterization is being shown when she realises that there is something going on between Amber and Guneet.
Guneet is love sticken, but she is herself when she commands that respect from Amber when he acts immaturely.
My personal opinion, everybody is entitled to make their own. I personally like Nia at this point being independent and not being with either Kabir or Rishi. With Kabir it's too good to be true, with RB, I feel uncomfortable with the kind of gaze he has and it is not romantic, it feels weird.