TexasCHLforum.com

https://www.cdc.gov/nchs/data/nvsr/nvsr65/nvsr65_04.pdf

Is the final tally for 2014 from the cdc.

32,295 total deaths for 14 years old, and younger. Sadly the next step is 15-24 which kind of throws the ability to check anything under 18 for the most generous definition of child.
50 deaths due to accidental discharge of a firearm.
174 deaths due to intentional suicide by firearm.
225 deaths due to assault homicide by firearm.
10 deaths of undetermined intent by firearm.
1 death by legal intervention (I'll toss this in as that could be police shooting someone).
460 injuries by firearm.

Works out to 1.26 deaths per day by firearms.

Total firearm deaths for 15-24 is 6,143. Sub 18 year olds would account for 30% of the age bracket, so just to give some kind of number if you take 30% of the total deaths gives 1,843. Not exactly accurate but blame that on the government not breaking the age brackets down where you can see legal minors, and legal adults. Gives you 5.05 deaths per day, add that to the above and you get 6.31 deaths per day by 17 and younger. Over 90 days would give you 568 deaths per 90 days; 113 deaths per 90 days for more what most would consider children.

These are small potatoes compared to vehicle accidents, 738% higher for 14 and younger. Vehicle accidental death for 15-17 is 93% higher. Deaths due to drowning is 40% higher for the 14 and younger crowd. Suicides by other means is 46% higher for 14 and younger.