Yes she is. She comes on popcorn. Telly chakkar had her interviewed. She was interviewed on craze FM. Every Kaisa Ye Pyar hai promo features her. She even appeared in a couple of promos which showed only her, not Angad or Prithvi. And I think I saw her on Star News too. I even read some magazine interview of hers on this site. I think that is enough publicity. She cannot perform because the character she plays is not a rockstar. I read somewhere asking why can't they show the KYPH cast like those of Kahani or KSBKBT. The answer is simple- One Kahani and KGGK are family oriented serials and they can show an entire family getting together- KYPH is not. Second, star being a bigger channel can organise special episodes for festivals where the entire cast of a drama can participate. Sony is too engrossed in its reality shows hence do not promote serials. But KYPH being a musical is somewhat related to these reality shows, thats why the rockstar is getting promoted.
Amit and Prithvi are not getting publicity because the villain or supporting cast do not get much publicity. The nature of the character has made Prithvi unpopular. And he is supporting cast. There are only two in the lead.