plc

I hope someone can help,my dtg who is 21 has recently lost about 40 lbs,(on purpose),She looks great,(was quite plump all though childhood)Had a physical,the doctor found her liver enzy. was slightly elavated.Recom,repeating in mo.,month later they were alittle lower...doctor states don't worry. Eight months have past and she saw a gyn doctor,she metion the liver test,she orders a set of tests.Results the liver tests are higher then before..See a gastro doctor 2 wks ago, Has ever test bld test in the book and a ultra sound...Just got all the results back every thing is neg...(thank god)however now the doctor wants to do a liver biospy...He told my dgt he felt that to will be neg,and if it is neg, he has no clue why her liver enzy.are high..Now my daughter does not drink,(can't stand the test),has no body tattoo's,had the hep b shot in high school...I'm afraid if the biospy is neg,then what do we do???The doctor is very nice and told me if neg,well I don't know what to say..Could the Lab be doing the test wrong? I am worried, Has anyone also have this problem??? plc