Singer of Caliber like Nihira ( & Hemu too) Should work toward being independent singer and should be known for their own songs now.
They should not waste their time in singing someone elses songs. ( though we all like it).
How many people knew Kumar Sanu when he used to sing Kishorda's songs ?
For all new singers - It is important to establish themselves as singers. Shows and Contests keeps you on the frontline only for short peroid. ( I understand shows are also finacially very lucrative).
But being on their own as singer by getting new films and albums is going to fetch them success in long run.
Nihira is the best, just waiting for her albums and other music release.