Apothecary Diaries
Frieren
One Piece Live-Action
The Way of The Househusband
Dr. Stone
Delicious In Dungeon
Canon Busters
Sakamoto Days
NIMONA!!!
Kpop Demon Hunters
Spy X Family
Bright
Romantic Killer
Violet Evergarden
Kakuryo - Bed & Breakfast for Spirits
Sakuna: of Rice and Ruin
'Tis Time For Torture, Princess
Kyousougiga
Fairy Tail
Solo Camping for Two
Sugar Apple Fairy Tale
Spice and Wolf: Merchant Meets The Wise Wolf
Usagi Drop
Secrets of the Silent Witch
With You and the Rain The Devil is a Part-Timer Buddy Daddies
The Eccentric Family
Zenshu
Dragon Goes House Hunting Seki-kun: The Master of Killing Time The Too Perfect Saint

The greatest difficulty lies in making yourself available to answer questions appropriately(by your parental judgement) and screening episodes in-advance so you can be prepared both for questions, and to raise/answer questions you believe shouldn’t be glossed.

It’s a 6-year-old kid for God’s sake.

Apothecary Diaries -> solving murders is the main theme. Plus prostitution, harems, blackmail, slavery, etc…

Frieren -> slow burn for adults that understand the concept of missed time and looking back. Not to speak about all the atocities done by the demons

The Way of The Househusband -> haven’t seen it but a Yakuza themed show …

Delicious In Dungeon -> sister dies gruesomely and gets turned from a bloody flesh mob into a monster that hunts her own brother and friends.

Sakamoto Days -> I think this one was assassin themed? Not sure.

Romantic Killer -> another assassin-themed show IIRC

Violet Evergarden -> lots and lots of very dark themes, including the war orphan origin of MC.

'Tis Time For Torture, Princess -> nothing wrong with this one, but I don’t know how entertaining it would be without knowing what it parodies (torture)

Solo Camping for Two -> adult drama/romance? Why not suggest Yuru Camp instead?

Sugar Apple Fairy Tale -> okay now I know that you are trolling.

Usagi Drop -> aimed at adults. Utterly boring for kids.

Secrets of the Silent Witch -> sure OPs daughter will enjoy MC losing her father due to being burned alive and all the assassination attempts.

With You and the Rain -> another show aimed at adults. The only thing that a 6-year-old would find interesting is that the “dog” is cute.

The Devil is a Part-Timer -> is it really funny to someone who hasn’t worked a day in their lives? Plus, again, the theme of dying parents in FMC.

Anything worth watching is going to have some dark themes, and don’t ask me why I haven’t recomended shows I’ve never watched.

There’s nothing on my list my own daughter hasn’t been able to watch if/when she wanted, as I was watching them. She loved The Devil is a Part-timer her first few years of grade-school. Same for Buddy-daddies, Usagi Drop, With You and the Rain. Have your kids never met a homeschooler, stay-at-home parent or adult who never moved out of their parents house?

I’ll admit I haven’t been able to get her watching Solo Camping for Two, largely because I’m waiting for it to be dubbed so we can watch it with my her mom, and we camp a lot, so there’s not-so-much novelty for her there.

Apothecary Diaries has murders? Well, I guess that would be its single biggest difference versus Disney’s Aladdin, what with Aladdin’s Brothel scene and … oh wait, no, Gazeem dies in the openning scene.

Frieren? Sure, every death is shocking, corpses too. The alternative is comfort with things, just because you don’t see that they’ve happened.

The Way of The Househusband has Yakuza characters doing every-day things. The fact they can’t even dress normally and don’t know how to act non-threatening is part of the humor. Meanwhile, the MC bakes cookies and takes the lunch he made to his wife at her job.

Sakomoto Days? The protagonists don’t kill, and the protag-faction grows by way of people they’ve spared realizing that killing is always optional, never mandatory(honestly, one of the more fantastical elements, considering the extreme situations portrayed).

Romantic Killer? What, your google-fu abandon you? No one dies or kills for a living in this one.

Lots of lazy counter-arguments and shows you-haven’t-even-watched in your comment, nevermind fully half of what you poo-poo’ed is on the, granted, hillariously-bad Bored Panda list linked by another commenter here.

Just about the only thing you’ve pointed out that isn’t covered by the Ghibli movies OP’s child has already watched is death, although one wonders if they watched the whole of Howl’s Moving Castle or any of Grave of The Fireflies.

Pretending grade-schoolers and Stay At Home Moms should never have to see or hear about death or naked people(my list could be over twice as long, but I read the room and chose my battle) has done such wonders for society. If OP were trying to raise one of the 53% of White Women who voted for Trump, they could hardly go wrong with your voluminous advice.