Attached are the two versions I made from a Poser scene.  The first is rendered with Poser, the second is the result of using a Photoshop action.  But the comment on both is they're not "kid friendly" enough.

I tried to find a crayon filter or action for Photoshop, something that would make an image look more like a child drew it, but without luck.

Any suggestions?

Well I don't know how old the child who drew the picture would have to be, but when I think "child drawing", I see something a little more naive-like...  Unless a child is gifted, he/she wouldn't really be able to draw a picture like this, with perspective, good distribution of shadow and light, good proportions, all the details, and I'm thinking that maybe this is what they meant?  That maybe it's not so much the render style that isn't what they're looking for, but the fact that it's a little too elaborate for a child's drawing?

Just my 2 cents...  Hope you won't mind...

Well I like the first one better for your purpose but the couch is too detailed and the relative reality of it takes away from the rest. I hate all that the eye is drawn to stuff because it sounds pompous and concieted but in this case; that couch ! ! ! I keep looking at it and can't concentrate on anything else - do something before I go cross eyed !! 

but seriously, the first one. 

(just a gentle reminder - 09/19/08(U.S.) is International "Talk Like a Pirate Day" )   

in case nobody mentioned this, as a former kid, I know how I drew stuff, which was:

big circles for heads, with eyes, mouth and hair
stick figures for body
circles with short lines for hands

I dunno if poser or D|S can do that.

Why Yes . Yes it can . . . I made my first Poser model that way as a  test  of the walk function . . . It scared me so much that I haven't been able to look at a Poser model straight in the face since ... and the other day I was driving and a guy in the next car cut me off.  I changed lanes,  looked over and just as I was about to call the driver who had done me wrong a clown, I noticed his red bulbous nose and frilly costume - which scared me even more.

Way too much depth for a child's drawing -- and I mean both versions. Children typically draw two-dimensionally. As someone has already said: stick figures and such. Might have been COLORED by a child, but not drawn.

That's what I thought, stick figures and such.  But I don't think this person wants stick figures as illustrations for her book.

I sent a question asking if it was the composition, and to clarify what she'd like to see in the image.

Here is her feedback on the image:

"The scene is great. I do want it with brighter colors and maybe like a kid drew it. Something for a 4-6 year old."

Obviously, you must give the client what they want, but what they seem to want and what they've asked for are not very consistent. :)

yeah, get into the client's head. I don't think either of you is gonna be happy otherwise. 

yeah, flibb, that's more like it!  but I reckon what she wants is something like "south park".
they are able to do scenes like the lady wants, but it relies largely on the sound trak AFAIK.

I can easily do the scene more in a South Park style with straighter lines etc.  But South Park doesn't look like a 4 year old drew it.

You're likely right though.