She's gorgeous.
The flat feet are something that really needs to be addressed by diet - there's not a lot the farrier can do about it, unfortunately.
How would I do that?
ETS they have actually improved a bit, they were flatter when I got her at 2 1/2 years
Trimming will help to an extent by keeping flare under control, but what can really make the difference is work and diet. Work you're on top of, and the diet doesn't sound bad either... however given that you've still obviously got issues there, I would start by switching to a better balancer. A better mineral balance (copper and zinc in particular) can make the world of difference to hooves.
I use the Forage Plus balancers, but Pro Hoof or Pro Balance + are also good places to start.
Her diet sounds fine for the amount of work she's doing, which is quite a lot for her age & breed. There's lots you can do without a rider, your long lining is a great idea - how about loose schooling? Throw in some pole work, some bending, ramps, spook-busting, a ball - anything to keep her mind occupied, but go easy on the lunging for her joints sake
I love Baileys Lo Cal, and you can also feed MagOx for her feet - I'd be careful about copper & zinc as they're easy to overfeed, whereas with Mg you can tell if you've given too much by their poo going runny/soft, and rectify immediately. If your farrier's doing a good job it'll be a few months before major changes happen anyway - keep up the good work I say, you obviously love her & she's looking fine!![]()