And while she has vowed not to let Amber's death make her unreasonably overprotective of Allison, McGonigle said a recent comment by a construction worker about Allison got to her.
""He said, 'Oh your daughter is beautiful.' I snapped," she said. "I yelled at him. It does rear up."
On Friday, parents of both girls used Gardner's sentencing to speak directly to him, to try to make Gardner understand exactly what he had ripped from their lives.
"You dismantled a family life that was built on love, trust and faith, but you did not destroy it," Kelly King, Chelsea's mother, said Friday. "Look at me!"
Gardner refused to look at her.
Parents of both teens played video tributes to their daughters.
"You have taken a bright shining star from this community and our world away, and for what purpose?" she asked Gardner. "To serve your sick, twisted, perverted mind."
"I hope you suffer 100 times the amount of pain that we have suffered because of your crimes," said Amber's father, Maurice Dubois.
Gardner also pleaded guilty to attempting to rape Candice Moncayo, a 22-year-old jogger, near the spot where he attacked Chelsea.
With his head bowed -- tears staining his kelly-green prison garb -- a seated and shackled Gardner occasionally contorted his face uncomfortably throughout today's hourlong sentencing hearing.
McGonigle said she got a glimpse of the rage Gardner has talked about during sentencing when Moncayo taunted him about his nose, the spot where she hit him to get away.