I think it belongs in veterinary. :) the hoof might show that somehting is wrong but the problem is frim higher up.
but for the visuals:
It's entirely possible not to show any signs if it's been a whole growth cycle since the last attack and with frequent trimming (or self wear). You can't say a horse never foundered by looking at their feet, in fact the goal should be not to leave any signs.
The laminitis attack will cause the bone and wall to separate and a wedge to form, in bad cases the sole may drop becoming flat or convex. A chronic foundered horse will have a curled toe from the continuous separation and wedge formation. A horse that has a single attack, propperly cared for will grow out a new hoof as the old damaged wall and the wedge grow out, there will be a marked line between the two. Farriers looking for signs of laminitis look for the dish and the rings on the wall and the wedge at the toe and bad soles. But that is not permanent, in fact if it stays for too long something in the managment or trim needs to change as the horses is still foundering. If the attack was very mild and propperly managed all they might get is a growth ring.
On a side note a horse doesn't need to have a laminitic attack to have a dished toe and a wedge, lowering the angle too much will have the same visible effect, without the lameness, rings, or problems with the sole. That is just the bone pulling itself back at the angle it needs to be and growing the angle of toe wall to match, while growing out the old low angle section. If you lower the angle at every trim you end up with a curled toe.
I think your recommendations sound good. If the pony develops a problem just cut the pellets alltogether and go to plain oats and mineral. Sometimes I think horses have a reaction to some ingredient in the mized feeds. With Dusty I think it was possibly alfalfa? he hasn't had gut trouble or bad hoof flares since I got him off pellets. I thought he couldnt have any grain for a while, they all messed him up, some more than others but he's been awesome on oats and prairie hay.
I would tell her to soak the hay for a few minutes in water before feeding it (not long and clean up whatever is left over). Grass hay can be high in sugar depending on when it was cut. Soaking the hay pulls a lot of the sugar out. She needs to make sure that she provides a good mineral/vitamin though as soaking pulls out water-soluble vitamins and all horses need minerals in this area. Feeding fats would be a good idea as well. Low carb concentrates and beet pulp wouldn't hurt if the ad lib hay isn't enough.
Also, beet pulp (non-molassesed is that a word?) is a good forage/fibre substitute for foundered gee-gees.
I had recommended the grains before she told me that the pony had foundered, so then I wasn't sure if they were still appropriate. I was thinking more about weight gain at that point. I'll tell her about beet pulp.
I asked who her vet is and got a blank look. I'll send her a recommendation of someone good in her area. I'm so glad this lady wants to learn!
she and her daughter were looking at heavily-pregnant Isabelle in her stall and the little girl, eight years old, asked me so sweetly if I thought Penny could have a baby too. I gave her my very edited version of how there are sooo many horses in this world and she could give another horse who is already here a good home rather than making a new one with her mare. Her eyes were so big, taking it all in. I swear I almost cried.
Another question would be to find out what the horse foundered from. If it was do to a random got-into-the-grain episode, then she might not have to worry so much about a repeat offense.
I'll see if they know.