in the 78 gerentions of claymore, 3 former nuraber 1 awokened. the first gerention of male (only gerenation) first gerention of female and Rafaela's sister from 76.
however, there was one more nuraber1 awoken, it's the nuraber 1 from Teresa's era.b/c of Teresa, the other girl was lowered to nuraber 2 and that pissed her off very badly and costed her to awoke.
so she send Teresa her black card predenting that she's going to get over her limit but in fact she already awoke. when Teresa showed up, she owned the former nuraber 1 with around 30% power.
so there u have it, with 30% power, teresa beat the 4th nuraber 1 to awake. is she as strong as the 3 before her? no one knows, but she is strong enough to be ranked nuraber 1 and it didn't take teresa that much to win