''I've been relaxed all day and as I was falling asleep, I started thinking, 'I'm driving tomorrow', and all of a sudden it's a bit daunting,'' she said.
Also intimidating is the fact that Dunedin-based Gilmour has not even driven her fully race-prepared Rhys Millen Racing (RMR) Hyundai Veloster Turbo rallycross car, built especially for her, yet.
Specifically decalled with pink stripes and tyre rims, it might have a feminine appearance but its heart beats full of testosterone. Its highly tuned engine generates about 441kW and, like all GRC cars, although it rolled out of the factory as a production model, it received significant improvements to its chassis, engine and safety features to bring it up to racing spec.
The first time she drives it will be in the two-hour practice session today at Barbados' newly renovated Bushy Park Circuit. At least its layout is forgiving for her debut, Gilmour said.
''The track is wide, not too narrow and is a nice circuit for me to start on.
''I didn't get to drive but I did walk the track. It looks really cool, quite fast and open, not a huge amount of gravel. The jump looks like fun.''
She expected to reach speeds of up to 180kmh on the predominantly tarmac course, which features two gravel corners and a jump.
Her experience competing in four all-tarmac Targa New Zealand events would stand her in good stead, she believed. Gilmour has also had some gravel practice this season, driving in two New Zealand Rally Championship rounds. The day after last weekend's Rally of Otago she was on a plane to Los Angeles, where she did a small amount of testing in RMR's lites team driver Tyler Benson's car.
''It was great just to get back into a left-hand drive car and do some tarmac driving,'' she said.
She then headed to Barbados earlier this week, where she met up with her RMR team.
Gilmour and team owner Rhys Millen will race identical cars in the Supercar category of the GRC's first round, which takes place in conjunction with Top Gear Festival Barbados.
The GRC race format starts with a one-hour qualifying today, where the field is broken up into small groups that take the track in 10-minute sessions. Seeding for heat races is determined by a driver's qualifying speed.
Depending on field size and track schedule, race day tomorrow begins with one or two rounds of four heat races, usually consisting of four cars and six laps each. The top two finishers transfer into the main event on Monday (NZ time).
All drivers who do not make it into the main event via heat races will compete in the last-chance qualifier for the final remaining qualifying spots. Ten cars then compete in the main event, which begins with a standing start.
Each course is equipped with two routes - the main route and the joker lap route, which each driver must take once per race.
Gilmour is just looking forward to finding out what she has in store for the United States-based GRC season's next nine rounds.
''I don't know what to expect as I've never done it before, but the team have been really great and supportive.''
Fans can catch the action at GRC TV, the Global Rallycross YouTube channel, and through the GRC's social media outlets, Facebook and Twitter.
