When TB treatment was given, my daughter developed hepatitis. Why?

Hi doctor,

My daughter, who was a medical college student, was suffering from high fever and the doctor ordered an x-ray and it turned out to be a pleural effusion. Cytology was negative, so was the polymerase chain reaction (PCR) for tuberculosis (TB), the fluid was straw colored lymphocytes rich 90% with some neutrophil and mesothelial cells. The adenosine deaminase deficiency (ADA) was 40. My daughter has been on clinical rounds at college. TB was diagnosed and treatment initiated. Her fever went away. After five days of Isoniazid (INH), Rifampin (RIF), Ethambutol (ET) and Pyrazinamide (PZ), she developed hepatitis. She complained of severe nausea and vomiting and was admitted subsequently, and all tests for hepatitis A, B and C and antinuclear antibody (ANA) were negative. She was discharged when the liver function test (LFT) returned to normal. Her doctor started INH and RIF and 3 days later she started having the same issues of severe nausea and vomiting. She was put on ET, Levofloxacin and Clarithromycin (allergic to Streptomycin). She went for a chest x-ray a couple of weeks later (two months since tapping) and found the effusion has not completely subsided, though it did subside a little bit since when it was last observed (a month earlier). The doctor is starting INH (third time) now. I am worried about the recurrence of hepatitis. I would like to get some advice.

Thank you doctor,

Also, she has put on weight since restarting Ethambutol (ET), Levofloxacin and Clarithromycin. Does the effusion take time to clear out totally? She has not been able to complete even a week of Isoniazid (INH) and Rifampicin (RIF). Will introduction of INH and possibly an extended run help is clearing out the effusion? Also, do you think she got TB through her clinical postings? What can she or her friends or young medicos do to avoid picking up diseases in future? Her effusion has shown a small reduction since a month. She only took INH and RIF for five days in that month. The effusion is very mild at the moment. It was moderate and unilateral (right lung) prior to tapping.