FitAndNatural

In this instance the issue is no longer height/weight but % of body fat, which looks here to be under 5%.

"Studies indicate that the body's fat content must account for 17% of the body's weight before menarche can occur and that, at age 18 years, the fat content must be at least 22% for the maintenance of regular menstrual cycles."

https://pubmed.ncbi.nlm.nih.gov/4053451/