10 startups that have grown with their millennial fan base by introducing baby and kids collections

It's no surprise that Brooklinen, arguably the internet's favorite bedding brand, is now making baby sheets and blankets in similar styles to their playfully patterned offerings for adults. Sweetly named "Brooklittles," the collection for tiny ones includes cozy blankets, quilts, crib sheets, toddler sheet sets, and swaddling blankets in ultra-soft materials like sateen and muslin cotton.

Read our full review of Brooklinen sheets.

Allbirds, the internet's favorite sneaker startup and maker of the comfiest pairs on earth, aptly named its kids' collection "Smallbirds" (we know — it gets us every time!). Toddlers and kids can run around comfortably in the company's original Wool Runners made from sustainable (and super soft) merino wool. Though the shoes have laces, there's also an elastic band underneath the tongue on kids' pairs so they slip on easily but won't slip off. Plus, parents can clean them up easily in the washing machine.

Read our full review of the Allbirds Wool Runners.

Recognizing that socks are one of the most requested but least received items in homeless shelters, Bombas was founded with a mission to provide socks to those who need them while selling socks to those who want them. The company has now donated over 10 million pairs. Their kids' socks are designed with grippy bottoms so they can run freely around the house without slipping, sliding, or crashing into walls (as kids are wont to do).

Read our full review of Bombas.

Launched exclusively online in 2014, Mahabis makes slippers for adults and kids that can easily be worn outside the house for errands, dog walks, grocery trips, and checking the mail. The original design for adults had removable rubber soles for indoor-to-outdoor use, but the newest iteration has them fully attached. The stretchy heel tab makes them easy to walk in, but they can also be folded down for a full slip-on experience.

Read our full review of Mahabis slippers.

Rent the Runway is now offering kids the same convenience of clothing rentals enjoyed by adults. Parents are now able to rent individual styles in the exact same way they may already do for themselves for weddings, special occasions, picture day, or family gatherings — all at a fraction of the retail price. If you have a Rent the Runway Unlimited subscription ($159 per month), you can simply include kids' styles in your rotation at no extra cost.

You'll find about 30 styles currently, some of which are mini versions of adult dresses that parents can rent for themselves (imagine the matching outfits!). Brands include Fendi, Marc Jacobs, Chloé, and more.

Read our full review of Rent the Runway Unlimited here.

Away's trendy suitcases feature ejectable batteries that are TSA-approved so your devices stay powered throughout your trip. The kids' versions are no different — they're just a little smaller and much more manageable for little ones to carry. They come in nine different colors, and Away also has a selection of fun and substantial stickers that kids can use to customize their suitcases.

Read our full review of the Away Carry-On.

West Coast startup Rothy's makes flexible, comfortable women's flats and loafers out of spun recycled plastic. This year, they launched a girls' line consisting of the ever-popular loafer style, which won't slip off their little feet as they run, jump, and play. As with the adult pairs, they're machine washable, comfy, and come in tons of fun colors and patters.

Read our full review of Rothy's flats.

Bedding startup Parachute, which launched in 2014, only took three years to put out its first collection of baby bedding. It now makes crib sheets in the company's beloved percale and linen materials, along with a selection of luxurious cashmere blankets, quilts, a pillow, and the sweetest little hooded baby towels you ever did see — all in gender neutral greys, whites, and pastel blush colors.

Read our full review of Parachute sheets.

Quip makes simple, sleek electric toothbrushes that have succeeded in making adults excited to brush their teeth. It was only a matter of time before they introduced a slightly smaller and softer kids' version (for ages 3 and up), which includes the same pulsating technology that lets little ones know when to move from one section of their mouths to another.

If you opt for the subscription package, you'll pay $25 upfront for the kids' brush base, a brush head, battery, and the company's own watermelon-flavored kids' toothpaste. Select the rate at which you'd like to receive new brush heads, and pay $5 per shipment, which includes a new battery for the base each time. For an additional $5, you can also tack on toothpaste replacements.

Read our full review of Quip toothbrushes for adults.

Known for its adult glasses that block blue light from computer screens, Felix Gray has introduced a kids' line that's available in both prescription and non-prescription styles. Considering that blue light is known to disrupt sleep cycles, and that kids tend to be on their tablets, phones, and screens a lot before bed, it makes sense for them to wear blue-light blocking glasses, too (especially if you don't want them waking you up all through the night).

Felix Gray's pairs come in three styles, each with four color options, and two sizes; one for kids ages 4 to 8, and another for ages 9 to 13.

Read our full review for Felix Gray glasses for adults.