How should I handle child characters? (Patreon)

Lately I been pointed out that my use of children on my Re-training classroom is an issue. 

I mean I have no intentions of them being in any way involved on topics  they shouldn’t be, that’s why scenes that involves them will not feature any sort of adult themes. I include them to fill a role on the story, a contrast to the irony of the character and it’s regression; like having a grumpy character being joined by a jolly one or a slim one partnered with a fat one. In this case a child being more mature than an adult.

That being said, I do understand that that it by association even while not explicitly they can get involved. 

The current kid on the comic will be on it just for a few pages more, and then gone from the rest of vol.2, yet I had planned that on the following volume there would be more child’s involved since Nagisa would be demoted to kindergarten.  But now ’m not sure that’s a good idea.

I been thinking how to handle this situations and narrow it down to 2 options … I ether get the entire volume reworked/ removed, or I change the way I depict children on the story. … maybe I could draw them as adult’s with a special visual indicator that they are supposed  to be children in the story role  ..  But I don’t know if that would make matters even worse. OTL.

So I have to ask you, do you think that would be a viable solution?