"I've known her on and off pretty much for five years," she told The Morning Edition host Craig Norris on Tuesday. "I had opened up my home to allow her to stay with me until she had gotten to her feet and gotten housing."
LeBlanc said during Allen's two-week stay within her home on Cedar Street, she watched her youngest son, Decklyn, 2, for "maybe only an hour tops." It was during that time that Waterloo Regional Police allege the toddler was poisoned.
"I didn't want it to be true," she said. "When I had gotten news that there were answers to why my son was sick in March and her arrest had been made, I was a little overwhelmed, angry, upset."
Hospital staff were suspicious
Police learned about the incident in March of this year, when staff at a local hospital became suspicious after LeBlanc's son showed the same symptoms on more than one visit.
Detectives believe the boy was given some form of over-the-counter eye product, one that can cause abnormal drowsiness, low blood pressure and breathing problems in young children.
LeBlanc said she first noticed her son's illness when her two youngest children were exhibiting signs.
"The one day, both my boys were lying on the couch with no energy," she said. "I've got a five-year-old and a two-year-old. If they're not running around playing, singing, there's something wrong …."
At first, she thought it was a bout of the flu, but while her five-year-old's symptoms eventually went away, Decklyn's symptoms persisted. LeBlanc realized that something was wrong when Allen suggested taking the boy to the hospital.
"I had no reasons to suspect that she had harmed my child," LeBlanc said.
Hospital staff, however, couldn't discount the possibility so easily. Shortly after hospital staff became suspicious, LeBlanc said she and her husband found themselves at the centre of a probe by child welfare investigators, but were quickly ruled out as suspects.
"That was when police informed me that there was an investigation going on with [the] fear that my son was harmed by this woman."
No idea her son was in danger
LeBlanc said the revelation from detectives came as a surprise.
"Honestly, I didn't realize my son was in danger. Like I said, her and I were close. I welcomed her into my home. I think I didn't want to believe it," she said.
"She kept on telling me, 'I did not and would never harm your children.' She swore on the life of her own children."
LeBlanc said the allegations against her former friend have been difficult emotionally for her family.
"The last 24 hours have been chaotic," she said. "I have an eight-year-old daughter who is completely distraught because she was close to Christine. That was her best friend. She called her 'auntie.'"
Worst of all, LeBlanc said the entire experience has left her fearful of leaving her children in the care of others.
"If it's not family, I can't trust anyone anymore."