Baby week by week · 3–6 months · 3–4 months: discovery

Your baby at 16 weeks

From Brittany Ryan, Founder and Mom of Two

What’s happening at about 3 months

Four months already! 💛 Your baby is becoming more interactive and intentional with their movements. They may be discovering that a kick can move a toy, a swipe can make a sound, and a smile can make everyone around them smile back. The tiny newborn days are giving way to a playful, curious little person who is eager to explore.

What’s ahead

As your baby's coordination improves, they may enjoy activity gyms, grasping toys, textured balls, and other toys designed for reaching, holding, and exploration.

A memory to keep this week

The first roll attempt you noticed

Safety first

Use close adult supervision for every activity. For sleep, follow current safe-sleep guidance and use a firm, flat approved surface. Keep small parts, cords, button batteries and magnets out of reach.

In the app this week

Try this together: Parent Survival Tip, plus this week's memory prompts, a private journal and your Journey, quick logs for firsts like tried to roll and held a toy. One simple idea at a time, never 47.

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Guided by: CDC milestones + AAP (HealthyChildren.org) + CPSC, written in Brittany's words.

Every pregnancy and every baby is different. This is general, educational information, not medical advice. If something worries you, check with your provider or pediatrician.

Meet our founder

Brittany Ryan

Founder and Mom of Two

Brittany is a mom of two with a background in early childhood development. Little by Little Together began with a beautiful, blank baby book. Like so many parents, she bought baby books with every intention of filling them; instead, they sat in a closet while life kept moving. So she built a personal assistant for parenthood that tells you what matters right now, offers one simple idea at a time, and keeps your story safe.

“You don’t have to remember everything at once. Little by little, there is a story worth keeping.”

Read Brittany's story

Founding 500 · applications open until Mother's Day 2027

Help shape the app as a founding mom

Open to moms and expecting moms across the US. Brittany reads every application; selected founding moms get Plus access. Fields marked * are required.

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I’m 18 or older, I’m a mom or expecting mom, and I live in the US. * I agree to the Founding 500 application terms (Draft, pending legal review), including Plus access for five years if selected. * I give Little by Little Together permission to use the introduction and other content I choose to submit to the Founding 500 program, with my first name, for app improvement and marketing. This includes publishing, editing for length without changing my meaning, and distribution across the brand’s website, social channels and app materials. Monthly check-ins are optional. This permission does not include my private in-app memories. * Send me launch news and sneak peeks. I can unsubscribe anytime. (Optional)

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