But they gave the Herald permission to publish their words.
The statements relate only to Christie being kidnapped and the aftermath.
Chand stabbed Christie to death while free on bail after being charged with the kidnapping. On Wednesday, he was found not guilty of the killing by reason of insanity, and so was not convicted or sentenced.
Victim impact statements can be given only at a sentencing after a conviction is entered.
Mrs Marceau said she felt sick when Christie told her about the kidnapping.
"The next thought that flashed through my mind was guilt. A mother protects her child - that's what mothers do. I started to think that the attack on Christie was in some way my fault, and to ask whether I should have seen this coming or done something," she said in her statement.
"From the date of the offending she changed. On the surface she was still happy and fun, but as her mother, I knew something was not right; she was a bit more distant, more withdrawn, cautious.
"The guilt I felt when Christie told me about the offending is still there ... The greatest impact, though, is that from the day of the offending I was robbed of my daughter. She became closed, distant and untrusting.
"When I remember Christie, I force myself to remember who she was before the offending. It is hard, given some of the memories I have. It is hard, but hopefully it will get easier ... I will remember that she was my baby, who I loved so much. She deserves to be remembered for who she was, not what Chand did to her."
In his statement, Mr Marceau said Christie seem to want to shield her parents from what happened to her.
"I talked to Christie about the offending, but only if she brought it up," he said.
"She told me how she had kept Chand talking, trying to appease him until he let her go. I was so proud of her - her resourcefulness and resolve.
"As a family we were concerned that Chand would attack Christie again. Christie was afraid.
"Christie was not herself after the offending. Most of the time she was still bubbly and happy, but Tracey and I noticed she was not quite right ... She was in constant fear that the accused would attack her again.
"Since the offending, I have tried to appear strong, together, and not like I'm coming apart ... I do this to support my family: I did it to support Christie and now to support Tracey.
"As Christie's father, I feel profoundly guilty for not being there ... for not protecting her. I have been told that it is not my fault, and I know it isn't. But this doesn't make the guilt go away."