Family here means the practical business of raising children and managing the relationships that form around them: the first weeks with a newborn, the years of broken nights and small emergencies, the long stretch in which a child needs steadily less supervision and asks steadily harder questions.
It divides into two. Baby covers the first year or two, where most of the questions are physical and immediate — feeding, washing, sleeping, and working out which of the day's alarms is worth acting on. Parenting covers the longer stretch, where the questions become behavioural and social: discipline, independence, siblings, school, and the business of two adults agreeing on an approach.
Sleep sits in its own place rather than here, because it spans both and because people arriving with a sleep problem want the whole of it in one view. It is under sleep, with the children's material gathered under children's sleep.
One thing is worth saying about this material as a whole. A good deal of it was written some years ago for a different readership, and has since been revised against current UK guidance. On this subject the guidance has moved further than on almost any other. How a baby is put down to sleep, what goes on a newborn's skin, how long a child stays rear-facing in a car — all have changed within a generation, and in several cases the older advice was not merely out of date but actively wrong. Where that is so, the revision says what changed and why, rather than quietly replacing one confident instruction with another.
The other thing worth saying is what is not claimed. Parenting advice is an unusually confident genre for how thin its evidence often is, and a fair amount of what gets recommended on health grounds turns out to rest on very little. Where something is well established it is stated as such; where it is not, that is stated too; and where something is simply pleasant and needs no justification beyond that, it is allowed to be.