The 49-year-old kiwi was a significant figure in Hamilton’s success, with the Brit winning four world titles during that time.
The pair announced the end of their professional relationship last year, but Hamilton has insisted that they remain good friends and has given Cullen enormous praise for her positivity.
In March 2024, Cullen made her return to motorsport as she teamed up with fellow compatriot Armstrong in IndyCar, as he embarks on his first full season in the category with Chip Ganassi Racing.
Since their partnership began, Armstrong has seen an up-turn in form, with two fifth place finishes and most recently, the 23-year-old achieved his first podium in IndyCar, finishing third in Detroit.
However, he endured a disastrous debut at the Indianapolis 500, suffering an engine failure after just six laps and forcing him out of the race.
Despite the heartbreaking result, Cullen kept his positive mindset and insisted that the team ‘will be back’ and would learn from the weekend.
And speaking with the Associated Press ahead of the Indy500, Armstrong spoke of the impact she has had on him already.
“She has all the experience in the world,” he said.
“She’s seen championships won, she’s seen how it’s done by Mercedes and all of that, so having her on board is a source of inspiration and guidance and motivation.”