My daughter used to show TWH too.
The Palm Beach County Mounted Posse Pleasure Show has walking horse classes. That's where we showed locally and it's the only show around here that has TWH classes. The other TWH shows she attended were put on by the FWRHA and were in Montverde, Ocala, Tampa, etc..
These are the TWH classes at the PBCMP show:
-- Model Walking Horse Halter
-- Plantation Open Shod Canter
-- Youth Plantation Specialty
-- Plantation Open Shod
-- Plantation Light Shod
And you can of course also show there in any of the saddle seat, western pleasure or english pleasure classes too.
This is their website:
Hope to see you there!