Kjær's design work blends modernist ideals with a human-centered approach, emphasizing functionality, adaptability, and simplicity. Her furniture designs are often characterized by clean lines, practical form, and the use of quality materials. In addition to her furniture work, she also created interior designs for various architectural projects, reflecting her deep understanding of how architecture and design work together to enhance the human experience.

Throughout her career, Kjær worked with prominent Danish design firms and collaborated with major brands, contributing significantly to the Danish Modern movement. Despite a relatively low profile in the global design scene, her work has gained renewed attention and recognition in recent years due to its timeless appeal and forward-thinking design philosophy.