How the child got hold of the cannabis capsule we will never know but I'm guessing it was dropped on the floor and anyone with children will know exactly what happens when a child of this age finds something on the floor.
It goes straight in their mouth.
The mother came home to find the child vomiting but instead of seeking medical help immediately she took the advice of one of the people in the house who said the baby "would sleep it off".
An adult might be able to sleep this stuff off, but I very much doubt that a baby could. It wasn't until later that night when the child woke with a high temperature and starting vomiting again that the mother sought medical help. And even then she didn't tell hospital staff what her child had eaten.
I'm sure she was scared of what the consequences for her would be, but at this stage she needed to come clean for the safety of her child.
Luckily this time the baby recovered. Hopefully there won't be a next time.