It is a common query online to find a "free PDF" of this book. Here is the reality regarding digital versions:

Despite her circumstances, her kitchen skills were legendary. She was reportedly able to make —a complex Indian sweet—perfectly by the age of eight. Relatives from across the country constantly besieged her with letters asking for her recipes. Tired of writing the same instructions repeatedly, her uncle, Rao Bahadur K.V. Krishnaswami Iyer, suggested she compile them into a book. A Pioneer in a Skeptical Age

For those specifically wanting a digital copy, official e-book versions are sometimes available. This allows you to read it on your phone or tablet legally.