[3] In 1981, she emigrated permanently to the United States where she worked as the senior acquisitions editor for foreign languages in the College Division of Houghton Mifflin in Boston.

In addition to writing, Campoy has also served on numerous advisory boards, such as the San Francisco Public Library, Leap Frog, and American Reading Company.

[7] Campoy's writing of over 150 titles covers a broad range of genres, from children's literature, poetry, textbook reading programs, and pedagogical books.

[9] She is the co-author (with Alma Flor Ada) of Gateways to the Sun / Puertas al Sol and has edited a number of anthologies of traditional folklore, poetry, and plays.

Campoy has also translated extensively from English into Spanish for authors such as Mo Willems, Gary Soto, Alice Schertle, Audrey Wood, Kathleen Krull, Lois Ehlert, Ellen Stoll Walsh, Mem Fox, and Gerald McDermott.