She was intrigued by the use of space and division in her artworks, mainly using shades of brown and green for this purpose. Instead of using a point perspective, she tried to identify space in a coulisse-like structure. The result is a division of space into squares and rectangles sliding over one another.

Nicole was a successful portrait painter and, with the usual ups and downs, she could barely make a living from it. She traveled to fairs and markets, like the Queens day market in Amsterdam, where she painted many random portraits, sometimes even portraying whole families. Her portrait of tennis club celebrity Gerrit Baljé can still be admired at the Festina clubhouse in Amsterdam. She often participated in beneficiary auctions; as a result much of her work is in private collections.