Welcome to HCM,
After going through your history, any one who is anorexic for so long develops nutritional deficiencies of various type, which reduces immunity not only risk of various infection increases also of malignancy(Cervical).
Absence of period is amenorrhoea may be due to other reasons also like Anemia,hormonal imbalance, Thyroid disorder
is known to be associated with HPV infection
, Please note there is vaccine available for it.
please take care Visit a Physician/Psychiatrist
and Gynecologist to examine her and investigate accordingly and once cause is detected she can be treated.