The jury found Krystal Khan guilty for the June 15, 2009 death of James Farrior.
Khan told police that she had dozed-off after taking Dayquil and Nyquil, even though she knew it caused drowsiness.
After Khan fell asleep, James tumbled headfirst into a mop bucket containing about 6 inches of water.
The 30-year-old Khan was convicted of reckless assault of a child by a day care provider and endangering the welfare of a child.
Khan, who has two children of her own, now faces up to four years in prison. Her attorney had said she was "extremely remorseful."