Cullen has revealed that a mutual sponsor resulted in the connection with Armstrong during the off-season.
The 50-year-old has now been working with Armstrong for the past few months, and has enjoyed her time in IndyCar so far.
“We had very similar values, we’re very driven, we’re very competitive, and I was really excited when I met him that he was that same way,” added Cullen.
“He said, ‘Do you want to come to a race?’ and I said, ‘Oh yeah, I’d love to come out.’ Oh my God, like IndyCar just hit me. It is so much fun, and I just fell in love with it.
“The racing is incredible, the drivers are incredible, I was overwhelmed by the expertise of everyone in the paddock. So I arrived, and I haven’t left.”