The pair won a Paralympic gold medal in 2018 but Maj Kehoe's retirement means they will no longer compete together.
Despite this, Fitzpatrick told Forces News that the bond between them "is never going go away".
"That partnership is never going to go away even if Jen stops skiing or I stop skiing," she said.
"That friendship has been built over years so that's definitely not going to change."
The timing of the exit has left Fitzpatrick searching for a new guide ahead of the next winter Paralympic Games in 2022.
She said: "It was quite a hard decision to make together, I suppose because we are a partnership and it was a joint decision.
"For me, it's particularly hard to find a good guide especially with so little time before the Games."
Watch: Major Jen Kehoe explains her retirement from elite sport.
She continued: "With the team helping, I’m getting close to finding one, which is good.
"Obviously, it hasn't had as much time and effort put in as our team 'Menna and Jen' did before the Games in 2018."
Fitzpatrick explained what made her partnership with Maj Kehoe so successful, saying: "One of the things that we really worked on was making sure there was no blame on anybody.
"If anything happened - whether Jen took the wrong line or whether I fell, or whether things out of both of our control happened - we made sure it was a team instead of any blaming, and that made us a lot stronger together."
Fitzpatrick said she and Maj Kehoe had bonded "quite quickly", adding: "I think it was when we went on a camp to Germany and I think we got the first lift.
"We were both so excited to give this new partnership a try.
"I think as the day went on, we just had fun.
"We bonded over the same sort of things and I suppose it really progressed from there pretty much instantly, I would say."
Cover image: Menna Fitzpatrick and Major Jen Kehoe competing. (Picture: Alamy)