There’s nothing like a baby’s smile to light up a gloomy day.

Even when a cranky relative claims, “They’re not smiling at you. It’s just gas.”

One new adoptive mom from Texas proved cranky relatives everywhere wrong, when she shared a video of her beautiful little one smiling on cue.

The video, posted to Facebook by the National Down Syndrome Adoption Network, shows 8-month-old “Baby H” lying on a blanket for tummy time.

Image credit: Facebook

When her mom asks how her day is going, Baby H smiles up at her.

Mom coos back that she loves her new smile and asks, “Can you show me again?”

After a moment, the little girl obliges, grinning from ear to ear.

Image credit: Facebook

Her mom is so tickled that she laughs. “Oh my goodness! I like that new smile.”

Thrilled with the attention, Baby H keeps it up.

As long as mom will laugh, she’ll cheese for the camera.

Image credit: Facebook

Children, and babies especially, change and grow so quickly that it’s always a joy to record precious moments for posterity.

This family was not only lucky enough to document their daughter’s sweet smile, but they were willing to share their delight with the rest of the world.

As they told the Daily Mail:

“You can tell by my laughter how much we adore this smile and she actually only smiled like this for a couple of weeks so this video is a treasure for us.”

They decided to share the video, courtesy of the National Down Syndrome Adoption Network, because:

“We hope that all the viewers will see the beauty that lies in people with Down Syndrome. Although a Down Syndrome diagnosis can be scary, the reality is that your child has a purpose and will be able to live a full and happy life.”

The video has amassed more than 300,000 likes and over 38,000 comments on Facebook.

Watch it and see for yourself.

Baby H certainly does light up the whole room, doesn’t he?

What do you think? Let us know in the comments!