Lana's CC finds has a toddlers section:
http://sssvitlans.tumblr.com/post/173617732979/sims-4-toddlers-stuff
The hair is separated by MM but, the clothing is mixed. They have a separate link on another page that is all MM toddler clothing:
http://sssvitlans.tumblr.com/tagged/ts4todmm%20clothes
Here are some MM pjs:
https://wlwsims.tumblr.com/post/169122844410/lil-whisps-pajamas-for-toddlers-11-swatches-for
http://sssvitlans.tumblr.com/post/161692932729/moonpie-sims-pure-heart-pajamas-hello
http://mamabearssims.tumblr.com/post/163561355417/little-girls-pajama-set-17-solid-colored-tops-17
http://mamabearssims.tumblr.com/post/163524624875/little-boys-pajama-set-16-solid-colored-tops-17
http://sssvitlans.tumblr.com/post/159200036519/comfysim-cutie-jammies-700-follower-gift-i
http://wildlyminiaturesandwich.tumblr.com/post/158516084774/more-recolours-and-a-child-toddler-slipper
http://josiesimblr.tumblr.com/post/156026025014/lil-monster-pajama-tops-for-toddlers-bright
https://simdoughnut.tumblr.com/post/156044223368/freezer-bunny-and-grim-bunny-onsies-by-simdoughnut
http://birksche.tumblr.com/post/159617144914/nigtynight-toddlerdress
https://simsworkshop.net/resources/plumbob-outfits-for-toddlers-tops-pants.2540/
https://silverhammersims.tumblr.com/post/176809084703/this-started-out-as-me-wanting-more-solid-color
https://moodaye.tumblr.com/post/173086952868/recolored-this-version-of-the-base-game-toddler
https://bahiixo.tumblr.com/post/172717361762/hello-3-and-welcome-to-my-first-cc-3-i-thought
https://sims4pose.tumblr.com/post/169793281480/download
http://sssvitlans.tumblr.com/post/166138280584/recolour-toddler-sleepwear
https://www.renorasims.com/product-page/kopie-van-toddler-hoodie-less-onesies
https://www.thesimsresource.com/members/Sonata77/downloads/details/category/sims4-sets/title/s77-toddler-set-02/id/1384654/
http://fuyaya.tumblr.com/post/158664414236/onesie-short-animals-im-back-with-this-little-set
http://fuyaya.tumblr.com/post/156032923977/pajama-monobi-here-you-go-32-solid-colors-ok
https://littlenoobooplumbobs.tumblr.com/post/163098059018/monobi-pajama-recolors-mesh-from-fuyaya-required
http://deelitefulsimmer.tumblr.com/post/161899690709/hello-my-fellow-simblrs-since-i-recolored-this
http://deelitefulsimmer.tumblr.com/post/161745243549/hello-my-fellow-simblrs-pickypikachus-sleepy
http://deelitefulsimmer.tumblr.com/post/156060526324/hello-my-fellow-simblrs-whew-this-was-a-huge
http://deelitefulsimmer.tumblr.com/post/155825126464/hello-my-fellow-simblrs-no-i-am-not-back-from-my
http://cabsim.tumblr.com/post/159091671559/guys-i-really-like-pyjamas-and-i-also
http://sssvitlans.tumblr.com/post/157540013854/nygirlsims-lace-trim-toddler-pajama-bodysuit-in
http://sssvitlans.tumblr.com/post/157534954939/pixielated-toddler-onesies-recoloured-20-solid
http://letichespixels.tumblr.com/post/157138123648/this-download-is-for-the-sims-4-this-has-8
http://saartje77.tumblr.com/post/156532775964/hi-guys-finally-stopped-being-lazy-finished
https://chillissims.tumblr.com/post/156073598894/recolor-sweet-dreams-pyjama
http://georgiaglm.tumblr.com/post/155982528288/toddler-onesies-i-converted-these-onesies
https://sites.google.com/view/hammerart/sims-cc
Really cute puppy and kitty slippers:
https://simlaughlove.tumblr.com/post/142689559818/sll-puppyslippers
https://simlaughlove.tumblr.com/post/137592025813/sll-kittyslippers