Did you figure it would be the smart thing to do to spread your seed in the hopes of a little mtb ripper army of groms? Yes? Well then you're covered. For about 1k you can have a 20" full suspension MTB with 80mm rear travel, front travel (at least on the one spec'd at the show) was a custom white brothers fork (they did some awesome 29er stuff years ago before anyone else gave a shit-damn)
Second option for you're even more vertically challenged midget ripper grom; a 16" wheeled hardtail with is disc tabs and "designed" around another 80mm fork, although this one wasn't another white brothers which has me pondering what other forks could be spec'd to make your child feel like one of the "BIG KIDS".
Pretty cool concept little bitty bikes for little bitty tikes
RIp off the training wheeels and start them young right? Hell YEah! I still say start them off on a BMX bike (they will thank you for those skills developed later) Think FMB 2028 bring-that-25k-check-over-so-dad-can-get-a-rat-rod...
Lil Shredders Shred Duthie Hill - More Mountain Bike Videos
lil' shredder bikes