She's old enough now that you can't keep her in a crib (what if she scales the walls in a break for it?), but she can still hurt herself if she falls out of bed in the night. She needs a toddler bed--low enough that she can climb in and out without getting hurt, with fixed railings that keep her from rolling out while she's asleep. The Oeuf Toddler Bed uses a standard crib mattress (not included), which lets her use a familiar mattress and saves you some money.