Found

Shannon failed to save the earth colony of N'arth.
Back on earth her life is a disaster. Her twin, Raylene, has alienated all her friends. Nan has disappeared. The police suspect Shannon of murder.
Shannon makes two new friends, Zharu and Mungo, but one will betray her.
Enhanced night vision, superhuman hearing, hardly sleeping and a strange marker on her DNA-What is Shannon morphing into?
Whatever it is, she's terrified of being captured, interrogated, and dissected.
Her only solution? Return to the pre-industrial world of N'arth. But how? And when she does return, what awaits her there?