Apparently it could have been caused by the child playing
with toys which have been handled by unwashed toilet hands
etc. and appears to be due to a bacteria of some sort!?

Rob, 
Foot and mouth disease is actually a virus, and is very 
contagious...............and hangs on for quite a bit, usually.......a real 
bummer to get during the holidays.  

I do have help though!  I have used CS to treat 5 different cases..........all 
in children under the age of 1.  I tend to be very conservative in my dosing, 
but this is what I did, and it worked.  I used 5PPM CS...........one teapoon 
orally twice a day......also rubbed the sores with a cotton ball soaked with CS 
4-6 times per day.  The sores showed major improvement within 24 hours, and the 
fever also broke.

I hope this helps.  Keep in mind that I used 5PPM and you are using 20 PPM, so 
adjust accordingly.  If there are still active symptoms after 24 hours, try 
increasing the dose..............although I never found that necessary.

I hope this info helps and gets her feeling better by Christmas morning,
Christiane