Maria Montessori (1870–1952) was an Italian physician, one of the first female doctors in Italy, who opened her first Children’s House in Rome in 1907. Below: a clear timeline of her life, the words she actually wrote, and which of her ideas you can still use at home with a baby or toddler.

The pros and cons of Montessori at home come down to this: it’s cheap, flexible and easy to start small, but it takes real patience, and the research mostly covers schools, not homes. It suits families who like borrowing ideas, and it’s a harder fit if you want a proven system. Below: the hard parts, and what you can skip.

Montessori criticism is a mix of fair points and myths. Some hold up in part: the “Montessori” label alone doesn’t guarantee quality, and there’s almost no research on Montessori at home. Others, like “it starts at age 3,” don’t survive a look at the sources. Below: each one, checked, and what it means before your baby arrives.

Montessori sensitive periods are stretches of time when a child is remarkably sensitive to one kind of activity, like moving, talking or putting things in order. Two Montessori organizations each publish a list, and neither gives a set age for each period. Below: how they can show up at your baby’s milestones, and simple ways to respond.

The Montessori planes of development are Maria Montessori’s four stages of growing up: birth to 6, 6 to 12, 12 to 18, and 18 to adulthood. The first plane is the one that matters now. It’s the age of the absorbent mind, when your baby takes in the world without trying. Here’s what that looks like at home.

The Montessori parenting style means raising your child with ideas from Maria Montessori’s method: respect for the child, real independence, and freedom within clear limits. It isn’t one of the parenting styles researchers study, but it lines up well with “authoritative” parenting. Below: 8 ways it differs from traditional parenting, and how to start for $0.