"After leaving the restaurant, Wes went to the gas station before going home," Mrs Peabody told news.com.au.
"But when he got home he did what he normally would have done and jumped out of his car, ran inside and played with the kids.
"About two hours later someone asked 'Where is Maya?' He said 'oh, sleeping with Grandma?' But she wasn't.
"He ran to the car and realised he'd forgotten her ... but she was gone when he found her. She'd died from heat stroke"
Local authorities have again warned of the dangers of children being left in cars after a NSW police were forced to smash the window of a locked car to rescue a toddler left alone in a car for three hours.
The child's father, Richard Ligault, said he was doing a school drop off after a "rough night" where the family hadn't slept.
"He fell asleep in the car and I thought he was at school and I went straight to work. I was very confused," he told reporters yesterday.
The NRMA says it has attended 581 incidents where children were locked in cars and 437 involving pets in NSW and the ACT alone, since October.
Last year 3767 kids and pets were rescued with the majority of cases being unintentional.
Mrs Peabody, who will mark what would've been Maya's 12th birthday later this month, said a simple change in routine is what killed their daughter.
"We always say muscles have memories," she said.
"My husband did what he normally would do on a Saturday ... thinking Maya was safe at work with me.
"When he found her, he drove straight to emergency."
Mrs Peabody said it was there in the hospital in the minutes after Maya passed away that she could either blame — or forgive — her husband.
"He blamed himself," she said.
"There was a point a few months after Maya died and I thought he was going to take his own life.
"But before they even stopped working on her, I had to forgive my husband for this accident, or I would destroy my family.
"Blame is something I could of easily done, but I chose forgiveness."
Mrs Peabody said the year following Maya's death was a blur, and it wasn't until 18 months later that she realised her baby was gone.
"In the first year, I really knew I had to keep family together ... so I ran through just holding my breath," she said.
"Because the kids had lost a sister ... so we worked on grief. In the second year, that's when you know it's real and that was really hard for me. I knew she wasn't coming home."
Since Maya's death, Mrs Peabody and her husband have been advocates for raising awareness about 'baby brain' in an attempt to save the life of another child.
Founder of Kids and Cars Janette Fennell, a US organisation that helps to raise awareness about the dangers surrounding children and vehicles, said the worst mistake any parent can make is to "think that this could never happen to them or to their family".
"That is the biggest mistake because if you really feel that way you won't put the safety tips and place that can assure it won't happen to you or your family."