Baby week by week · 18–21 months · 21–22 months: social practice

Your baby at 91 weeks

From Brittany Ryan, Founder and Mom of Two

What’s happening at about 21 months

Your toddler may watch other children closely and play beside them more than with them. Sharing and waiting are still emerging skills that require adult support. Temperament, sleep, feeding experience and opportunities to move all shape what you see.

What’s ahead

Imitation with peers and short cooperative moments may appear. There is a wide window for emerging skills.

A memory to keep this week

A brief sharing moment

Safety first

Use close adult supervision. Check every item for choking, strangulation, tip-over, water and fall hazards. Keep button batteries, magnets, medicines and household chemicals locked away.

In the app this week

Try this together: Two of the same, plus this week's memory prompts, a private journal and your Journey, quick logs for firsts like watched another child and copied a play idea. One simple idea at a time, never 47.

Become a Founding Mom Join the launch list

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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Why would you love to be a founding mom? *

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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