Three months old is the age at which your baby transforms from an adorable but somewhat passive companion to a true playmate. Around 3 months old, she should start to babble, laugh and hit you with real smiles that aren't just caused by gas. Playing with your baby is easy because she'll be readily amused by little things and won't be bothered by repetitive play. Expensive baby toys may delight her in coming months, but for now, all she needs to be entertained is you.
Lay your baby on her tummy on a blanket. According to MayoClinic, a baby this age should have 20 minutes (or more) of tummy time per day, which helps her strengthen her neck and shoulder muscles. Gather some toys or other baby-safe household objects nearby, then lie down on your stomach in front of her so your face is a few feet from hers.
Walk your fingers up and down and back and forth in front of her for a few minutes. Make them dance and skip quickly too, scuttling toward her like they're going to catch her. She might happily watch your fingers dance around, or she might try to reach out and grab them.
Place one toy at a time in front of her, far enough from her face that she has to reach for it. Let her grab each item and play with it for a minute. Give her blocks, rattles, soft balls, sturdy vinyl or cloth books -- any baby toys that can't hurt her when she inevitably mouths them. Take an item away every few minutes and replace it with something new for her to explore.
Continue showing your baby items until she starts getting fussy or seems disinterested. Scoop her up into your lap so she faces you, or sit her up in front of you wit support behind her since she probably won't be able to support her head until she's about 4 months. Make faces at her, play peek-a-boo with your hands and initiate a conversation. Enjoy the smiles meant just for you. She should be interested in mimicking sounds at this age, says HealthyChildren, so try talking to her -- leaving gaps in your speech for her to "respond."
Turn on music with a strong beat. Clap your baby's hands or tap her feet against the floor in rhythm to the song. Hold her as you dance slowly around the room, singing or humming along to encourage her to babble along.
Carry your baby around the house, around the neighborhood or even around a grocery store. Stop every few minutes so she can examine whatever's nearby, as you narrate everything. For instance, walk around the living room saying things like, "Let's look out the window. I see a car! I see a bird!"
Settle down with books on the couch or in a rocking chair. She might not be interested in books yet; according to PBS.org, but in another month she will be interested in exploring baby books with mouths and hands. At 3 months she is probably already enjoy repetition in stories, rhymes and lullabies you read and sing to her. Sitting with her, quietly cooing the words of a story and letting her touch the pages is ideal for helping her wind down before a nap.