Children of the Lens by E.E. Smith

Constance Kinnison did not waste much time in idle recriminations, even at herself. Realizing at last that she was still not fully competent, and being able to define exactly what she lacked, she went to Arisia for final treatment. She took that treatment and emerged from it, as her brother and sisters had emerged, a completely integrated personality.

She had something of everything the others had, of course, as did they all; but her dominants, the characteristics which had operated to make Worsel her favorite Second-Stage Lensman, were much like those of the Velantian. Her mind, like his, was quick and facile, yet of extraordinary power and range. She did not have much of her father's flat, driving urge or of his indomitable will to do; she was the least able of all the Five to exert long-sustained extreme effort. Her top, however, was vastly higher than theirs. Like Worsel's, her armament was almost entirely offensive -- she was far and away the deadliest fighter of them all. She only of them all had more than a trace of pure killer instinct; and when roused to full fighting pitch her mental bolts were weapons of as starkly incomprehensible an effectiveness as the sphere of primary action of a superatomic bomb.