It's a fragment, of a sentance.
Get slip resistant footwear and watch for signs <span />
Answer:
The medicine making her sleep.
Explanation:
Shes not afraid of it making her sleep, but she's afraid of it killing her.
Adding -s is the most common. for example: books, cups, pencils, etc. -es might have been the one that confused you, but that isn't a super common ending for plurals--instead, a more common one would be "-ies" which is when you drop the y (berry becomes berries, for example).
