A Kitchener, Ont. woman has pleaded guilty to poisoning four children under her care after lacing their drinks with over-the-counter eye drops.

Christine Allen, 32, was first charged with administering a noxious substance after a two-year-old boy she was babysitting was taken to the hospital three times in five days.

The young boy seemed drowsy and lethargic and was placed under medical observation for two days.

A day after his release, the boy returned to the hospital displaying similar symptoms.

Family and Children’s Services was called in to investigate after the toddler was hospitalized for a third time.

At the time, police alleged that a child in Allen’s care had also been taken to hospital with similar symptoms three years earlier.

Police say Allen was running an unlicensed daycare out of what was then her home on Millwood Crescent in south Kitchener at the time.

Details from the court note that Allen forced the child to eat hot sauce and dish soap and also forced the six-year-old to stand for a prolonged period of time while holding several books.

During the span of the investigation, police say seven additional victims from the Kitchener and Guelph area came forward alleging they were poisoned by Allen.

One of the victims was allegedly poisoned from birth to the age of fourth-months and suffered developmental delays, according to experts.

Police believe the children were given an eye care product containing a substance known as tetrahydrozoline, which Allen placed in the victims’ drinks.

Investigators say the victims include eight children and one adult.

Allen was charged with a total of nine counts of criminal negligence causing bodily harm and nine counts of administering a noxious substance.

She pleaded guilty to four counts of administering a noxious substance with intent to cause bodily harm in court on Wednesday.

With files from CTV Kitchener