"Administration of daily doses of up to 300 mg of melatonin without causing clinically significant adverse reactions have been reported in the literature.
If overdose occurs, drowsiness is to be expected. Clearance of the active substance is expected within 12 hours after ingestion. No special treatment is required."
https://www.ema.europa.eu/en/documents/product-information/circadin-epar-product-information_en.pdf
Maybe parents should be educated about the fact that it isn't dangerous in overdose, rather than publishing clickbait stories?