"Inside was something small and white, which she described as a tooth — looked like rocks, or pebbles. Then I was curious," Ms Straker said.
"She comes back, 'Well Mummy, I have a lot of his teeth,' so then I have a third capsule," she said.
That's when the mum contacted police.
"This can't be what I'm thinking it is, because how could that be in a preschool?" she said.
Local New York Police confirmed Ms Straker's suspicions after testing the capsules.
"Low and behold whatever this test kit is, it was blue and he said, 'This is what it is. That's what that means. This is crack cocaine.' I said 'What? Come again? No, I didn't just hear that," Ms Straker said.
She rushed her daughter to the local hospital because she was acting out of character.
"She couldn't sit down, she was beyond bouncy, very loquacious, just all over the place, literally, talking to herself, looking in the mirror, saying she sees three of herself. Once they did the urine test it came back positive that she had cocaine in her system," the horrified mum said.
The director of Serenity's daycare centre, Yvette Joseph, believes the capsules were thrown over the fence of the daycare centre, but police say one child was passing them around like candy.
"Whatever it was, we think the person threw it over the fence to get rid of it," Ms Joseph said
"We did a thorough check. The children are fine. We called the parents."
But Serenity's mother wants the authorities to close the centre down.
"I want the school to be shut down. I don't feel it's safe for anybody's child. If they can't keep eyes on them, the don't need to be in their care, because this is something very serious," she said.