Yes, she is excellent ! In fact, I am surprised how she and Abhas did not top the competition....
My guess as to why they didn't hear Sumitra was her one quality: voice, and a variety in singing. Also, she emotes a song exceedingly well. Probably that is why she did not get listed in any of the judges choice this round.
Like, personally, I don't like Ismeet's voice...it does not have the required depth that one would remember hours after his song is done. His voice is, as best, mediocre, though technically, he sings well.
If you are talking of a variety in her tonal quality that he expressed in 'Hare Rama Hare Krishna', thats one thing.. but if you talk about her variety in choosing songs, I am sorry to say but she has not displayed that so far... Also, her voice seems to loose the edge at the higher notes, so am not too sure about the tonal quality as well!