My granddaughters take melatonin 3mg or benadryl (diphenhydramine) 50mg for sleep each night. is this safe. they are 10 and 12 years old.

NO: It is not safe for pre-adolescent or adolescents for that matter to be taking any sleeping aids of any type. At this age sleep should be a common end of the days activities. Please advise accordingly.

Melatonin: If effective and as recommended by a child specialist. I would not advise high dose on regular basis, though. Parents need to review with their doctor the reasons for lack of sleep and remedy those.