Your baby can't sleep with a baby pillow until she's a toddler.
Babies should sleep on a firm, flat surface free of pillows, blankets and other soft bedding until at least age 1 and preferably age 18 months or later, according to the American Academy of Pediatrics’ safe sleep guidelines. During her first year, the only thing your little one’s crib or bassinet needs is a simple fitted sheet.
As for when to introduce a baby pillow? Research hasn’t shown exactly when it’s 100 percent safe to put a pillow or other soft object in the crib, but the Consumer Product Safety Commission notes that pillows become much less risky past the 18-month mark.
To play it safe, you’re better off waiting until she transitions to a toddler bed, which can happen between 18 months and 3 1/2 years (and the closer to 3 years old you can wait, the better). Not only does waiting longer further reduce suffocation risk, but keeping a pillow out of your toddler’s crib means she won’t be able to use the baby pillow as a step to try to climb out.