Advice ASAP please !!!!

My husband left this bottle of melatonin out and left the lid open. I seen my daughter playing with it but didn’t realize it was open until she came to me with some in her mouth and I’m assuming she ate some as well. They’re a month expired and I don’t know how much she ate. These are for adults and she’s only a year old. Can she overdose on these ? Will she get sick? Is there anything I can do to prevent anything? Should I worry ? Because I’m freaking out right now.