Bagust also said the early morning starts had taken their toll.
"The 4am starts for two years have been huge, and initially Hamish was concerned about the impact it would have on the family. I've always been optimistic - and survived pretty well," she told WW.
"But for our family to work right now, the cost of my work is too high ...
"You can only absorb so much, 'Mummy, please don't go to work tomorrow' before it accumulates."
Bagust said she had no plans for the future when she finishes up at Breakfast on December 21 apart from going camping with her children.
At the time of her resignation, Bagust said two years of Breakfast had been a "rollercoaster ride".
"Breakfast is bloody hard work and it takes a lot of effort from an incredibly committed group of people to make it happen.
"I want to say thanks for having me on the team. Bring on summer and 2013."
Bagust isn't the only high-profile presenter leaving TVNZ shortly, with Mark Sainsbury stepping down from a redesigned Close Up at the end of November.
- nzherald.co.nz