Can a saddle clamp be upside down on a children's bike? Generally, when we put a saddle clamp on we put it so the rails are mounted on the "top" side (reference clamp pictured):



However in my case I still need to lower a seat by a inch more.  Looking at the clamp I could do this:



I'm asking this for my kids 16" bike.  She fits the bike well, but has a little issue of getting up on the saddle.  There appears to be enough space in the saddle to flip the clamp.  She is on the petite side at 15kg (and for reference, same model bike, my son was 23kg when he retired it).  I do plan on flipping it back over before I extend the seat post though.  

Does this work or will I run into issues?

I went ahead and did it, it was just right amount she needed, didn't even mess with the lock on the rack.



EDIT

Not to take away on the answers here.  My daughter has been riding this bike like this for just under a year now.  She has even taken it off a simple 2x4 and plywood ramp without issue.  I'm sure it will handle most kids, but since she is on the small side then I can't really answer as such.
Ask yourself which is stronger.  In the correct orientation a downward force would need to sheer the bolt to come out the bottom.  In the incorrect orientation a downward force just needs squeeze through the gap (bend a relatively thin plate just a fraction).  It is not designed to take force in the that direction.

And you have to consider stand over. If you get the seat low enough then your stand over will go negative.  Even if flipping worked you are going to be close or into a negative stand over.

And need room in the seat to be flipped.

Have you even tried this?

Oh, this is for light child? Light child is not likely to break a seat clamp even in a compromised orientation. Kids are not disposable but they are hard to break. Even if (and that is a big if) the rail blew out one side it is not even likely a trip to the hospital. A blow out to the front tire is more likely and will have the same scraped knee and tears.