Inez Eudora Perry was born in 1871 and lived until 1961, so her adult working life spans roughly six decades, and only four years of that, 1920 to 1924, were spent as an active co-author with George W. Carey. Every other year of her public output, from 1924 until her death, was hers alone, a fact the founding book's continuing fame as a joint work tends to obscure.
That solo period is where her own priorities are visible most clearly. She kept teaching through the Carey-Perry School and kept publishing, including a further collaborative volume, The Zodiac and the Salts of Salvation, and her own Esoteric Analysis and Synthesis of the Zodiacal Signs and Their Physiochemical Allocation, both appearing in 1932, eight years into her time carrying the system by herself. Later titles credited to her push into the late 1940s, close to three decades after Carey's death, and describe themselves as recovering or systematizing the underlying method rather than departing from it.
None of this changes what the system claims or how well those claims hold up as anatomy, chemistry or scripture, which this atlas records elsewhere as the tradition's own position rather than as established fact. What it does establish is a plainer biographical point worth stating on its own: this was not one book by two people that stopped when one of them died. It was one person's sustained project for four decades after her collaborator's death, longer than the partnership itself.