Grinnell became the group COO of Marjan in October 2025 and assumed her role as Marjan Hospitality’s CEO in May 2026, where she oversees the development and asset management of Marjan's hospitality assets. Marjan is the investment, hospitality and lifestyle company in Ras Al Khaimah, with projects like Al Marjan Island, Marjan Beach, and RAK Central. Grinnell led the partnership with Wynn Resorts and Marjan to develop Wynn Al Marjan Island, the region's first integrated resort. Prior to the merger between Marjan and RAK Hospitality Holding in October 2025, Grinnell served as CEO of RAK Hospitality Holding, following her role there as CFO.