Is It Safe For A Child To Take 10ml Of

Is it safe for a child to take 10ml of benadryl and 3mg of melatonin? Perhaps 30 minutes in between. She is 8 years old and she doesn't go to sleep well on her own. I gave her 10ml of benadryl to help her sleep. My husband didn't know and gave her 3mg of melatonin. And now I am worried and watching her breathing throughout the night. I'm also waking her up now and then to make sure she is ok.