Last year, the world championship motocross rider won both races by a comfortable margin.
The 23-year-old said the layout was pretty similar again and she was hoping for the same result when the series resumed in Agueda this weekend.
"It was a double win for me last year, so, yeah, I had a good weekend," she said.
"I enjoyed it last year for sure. It is a cool layout with some fun jumps.
"[The track] is probably going to be quite a lot drier because it is a little bit later in the year. There are nice warm temperatures here at the moment and it is forecast to be a sunny weekend."
The Dunedin-based rider is looking forward to race day. The opening round was in the Netherlands seven weeks ago, so it has been a lengthy break.
She returned to Dunedin during the competitive hiatus and "put in a good block of training".
"I'm feeling like I've made some good gains since I last raced."
Duncan had a mixed opening round. She was too quick for the field in the opening race but crashed in the second and eventually finished seventh.
That saw her drop to fourth place in the overall standings. She is five points behind series front-runner Amandine Verstappen, of Belgium.
The lead can change rapidly in the series, though. A win is worth 25 points, so Duncan is still very well placed.
She has been trying to win the championship since making her debut three years ago but a run of unfortunate events has conspired against her.
This year, she has switched teams and is now riding a Kawasaki. She had been riding a Yamaha for the past 10 years.
Duncan has quickly adjusted to the new bike and feels the set-up better suits her riding style. Handling is more important to her than power and anything she can do to stay upright will go a long way towards her achieving her goal.
She is the fastest rider on the circuit when she can stay on her bike.
That gives her enormous confidence, but there is alway a little bit of nerves.
"It is probably more excitement than anything else, really. The first race of the year is always the most nerve-racking.
"But I know where I sit and what I need to do, so I feel a little more relaxed going into this weekend."
