Cullen parted ways with the seven-time world champion last year, with the physio taking some time off from motorsport to complete a series of solo adventures.
Cullen has since returned to a role in motorsport, joining the camp of IndyCar star Marcus Armstrong this season.
The Kiwi has hailed the impact Cullen has had on his career thus far, claiming his first IndyCar podium after finishing P3 in Detroit.
Ahead of the Indy500, Armstrong revealed his physio was a ‘source of inspiration’, particularly with her experience in motorsport.
Armstrong also detailed her experience with Hamilton playing an integral role in her work, with her understanding of how championships are won.
In a recent interview on IndyCar’s official YouTube channel, Cullen was asked about her experience in F1, and what makes an athlete great.
“There are athletes that are good, and there athletes that are really great, obviously you worked with a great one [Hamilton], is there something innate about great athletes at this premier level?” the interviewer asked.
“All great athletes, the thing that makes them different is their focus, their dedication, and their belief that they have this true purpose which is to be the best,” Cullen said.
“You’ll find that across all sports.
“They sacrifice everything for this one dream and it’s so inspiring to work with these people and have them achieve that.”