Early on, Penny worked as a family doctor and in child health. When breastfeeding her first baby she realized the then standard advice to breastfeed every four hours for ten minutes each side simply couldn't succeed for her or, indeed, most other women. This was because it was based on bottle-feeding schedules and took no account of how breastfeeding works. Burning anger at having been let down with faulty information, plus an enormous amount of research, and the desire to ensure that other women could easily access accurate and empowering information, led Penny to write 'Breast is Best' with her husband, Andrew. This much-loved book has been in print in various editions and languages ever since. Its aim is to enable breastfeeding women to overcome any challenges and continue for as long as they and/or their babies want.