In 2009, Ms Watson and her sister Maria McKenzie rescued toddler Quentin Hemo-Puhirere by lifting an 800kg miniature train engine off him after he became pinned underneath it in Masterton's Queen Elizabeth Park.
The sisters lifted up the engine and pushed it back two metres.
At the time Ms Watson said she was unsure how the pair had managed to lift the train.
Ms Watson's last day as a Masterton senior sergeant was last Friday.
She starts a new role as Hutt Valley response manager, based predominantly in Upper Hutt, next week.
"It's just time for a change, to work in a bigger area and get different experiences, the Hutt Valley is probably the biggest [policing] area in the Wellington District," she said.
Ms Watson first came to Wairarapa in 2003 as a constable for the Masterton police and was promoted to sergeant in 2005, joining an all-male sergeant team.
In 2010 she went to work at the Police College in Porirua. She was promoted to senior sergeant and she worked as a leadership, management and command trainer, running the qualification courses for police who wanted to be promoted.
She suffered a serious head injury later that year and could no longer travel between Masterton and Porirua so applied for, and received, a senior sergeant position in Masterton in 2011.
Ms Watson said Wairarapa had been a great place to work and that it felt "a little bit odd leaving".
"You're living in your own community and there is a lot of knowledge and pride in what we do. Masterton has been my home for the last 10 years, and the station, and all the staff in there."
Wairarapa area commander Brent Register said the Wairarapa police area wish Ms Watson all the best for her career in Upper Hutt.
"We will miss the work ethic that she brought to Wairarapa and her buzzing personality."
He said Ms Watson had dealt with the Carterton balloon tragedy "very professionally with a lot of compassion".
"It was a tough thing to deal with, no one in New Zealand had ever had to deal with anything like that," Mr Register said.
Ms Watson was also involved in the search and rescue for missing runner Alastair Shelton in the Tararua Range last December and the search and rescue for Michael Hopkins on the same day. Mr Hopkins drowned after the boat he was in capsized in the Waiohine River, also in the Tararua Range.
Pahiatua station officer-in-charge Jymahl Glassey will take over from Ms Watson and starts next month.