It depends how you define what star means for you. If you define it as someone who is well known, than it will be only those who have been skating seniors for quite a few years. Most of non skating fans would never heard of those that have been suggested above.
I define it as someone who made a huge progress. AlexRus, you think that Gosviani is not a star level because she was 'only' 6th at Europeans. From the way I see it, if someone did not get named at international team within their country, nearly did not qualify at their nationals (or qualified only as 3rd substitute) and then ended up as 6th lady within Europe, that is success. It is a progress and hopefully breakthrough.
The same with Anna Pogorilaya. A year ago at junior nationals she was 13th, this season she was 3rd at JGPF, 5th at senior nationals, and 3rd at junior worlds. That's pretty good progress. She may not be a star in the meaning that people would recognise her on the street, but it is a significant improvement in her skating. In my opinion she is a star.
In regards to Sakhanovich, maybe she is not stable enough. But she is definitely impressive for her age. Being 4th at senior nationals at the age of 12 is a huge achievement, especially when you have such a high level of skating within the nationals. (I believe, when Adelina won the senior nationals at the age of 12, she did not have triple-triple in her SP. Now the majority of skaters have it in the SP in your senior nationals.)