with our generation today, hard to come by hard copies of comic books itself. let alone, telling a story about bitcoin. there may be online comics about crypto or bitcoin, but hard copy, that i doubt.
if not with comic books, the OP can always teach his young relatives how to install electrum, which is a very lightweight one. and try sending them some satoshis. so they will also learn how to take care of their own crypto wallet, just like many other digital wallets existing today.

I tried searching for such books but got no positive response from Google and Amazon and it is fine to teach children about bitcoin  especially  in a comic way but don't we think, we're pushing things too hard on them?
At some points I just think feel most persons who want to introduce bitcoin  to their kids are doing so out of regrets and hence wanting to use their kids to correct their mistakes and wanting them be better off in the future then their peers which I don't see as necessary because what will be, will be.

Rather than teaching your kids about bitcoin  now, why not get a portfolio for them and help them save,  by so doing,  when the time is eight fir then to dive into the industry,  it might be much more easier for them.

Just my unpopular opinion.

I love the idea about the comics it will make them more interested and i give them a better understanding since kids love cartoon, since the brain is still developing, therefore it's another option for the writer to generate money, but the write-up and images can't be too detailed because their brain is still developing and can easily break down the material.  when i saw your comment i was impressed did not think of this, Even in schools, with the help of cartoon graphics, children gain a great deal of interest in schoolwork, especially when it incorporates games and other entertaining activities, and if you can accomplish it, you can pursue the idea.

Actually, it's all about books comics about Bitcoin, it will be easy to get, because the technology is getting more sophisticated, they will know how to do it to publish about the title, but in my opinion the problem is implementation for a child who is still at an early age, because he is they are still focused on their world of play, after all Bitcoin is a currency equivalent it's just that it is digital, and sometimes they don't know about money completely.

I believe that children should have the opportunity to enjoy their childhood and participate in age-appropriate activities. It is really not advisable to introduce Bitcoin to children forcefully and take away their childhood. Prioritize their overall health and allow them to grow naturally without undue pressure. If your child really shows an interest in learning about Bitcoin while listening to you talk, just approach it in a responsible and age-appropriate manner. It would be better to address their curiosity with such suitable explanations.

I know you love your children and you want them to be the best in the society that is why you want to start showing them Bitcoin picture so that when they grow up they will have idea on Bitcoin in the society and start enjoying the benefits that attached to Bitcoin. I will advise you to allow those children reach 17 or 18 years before you will start teaching them or showing them picture of Bitcoin, because they will be mature at 17 or 18 years to control themselves when you are not with them in the school or at home. If what you are doing with Bitcoin in your environment make sense, I believe you children are watching and they will definitely ask you some questions that relate to Bitcoin and cryptocurrency that will make them show interest on it in the future.

You definitely shouldn't force children to study Bitcoin but in this case the OPs idea about the comic books is very appropriate. It's a great way to explain Bitcoin to them without shoving it down their throats. Actually, it's a great business idea too, perhaps you should start selling Bitcoin-themed children's books on Amazon?   

Although we know that bitcoin is not a common topic, it should be as simple as possible to explain to children and the future potential of digital currency. Children should be taught the decentralized nature of Bitcoin and the blockchain technology it operates on. Then it won't be that difficult to know what Bitcoin has to do with the future economy of tomorrow. To keep pace with the global economy, today's kids must know about the digital currency Bitcoin.

Shouldn't children from that age group be taught other things about life and how things work? I mean there are probably a lot of other things that children aged 7 to 11 years should learn first before they get into something this complex. I know that Bitcoin is the future and they have to learn about it eventually, but I don't think that they've reached the age to dive into it and they should be given some more time.

Children should be taught about Bitcoin and similar technologies after they become 15 at least, before that, they should be taught other principles of life and stuff which are also very much important for them to learn, when they reach that age, they will have enough understanding to grasp the concept.