Tawney created many assemblages—sculptures made from various items she collected. Like her two-dimensional collages, the assemblages show how she creatively reimagined the material world around her. She used unexpected and poetic combinations, often including bird-related items like feathers, eggshells, and bone.

She named this work “Pia Avis” after the “devout bird” described in the book Alchemical Studies by Swiss psychiatrist Carl Jung (1875–1961). In alchemy, this bird is an ancient symbol merging the spiritual and physical worlds.