A must have is Skinner's Salve which is good for pretty much anything (cough, burns, itch, fever, etc). You can go to their website and get a 1 oz sample for free. It will last you a while.
If you are ordering from MH, the PICA is good for minerals and I always have back up of Max Restore for when they are sick / coughing. If you can, get some Echinacea Rt for fighting infection and Calcium Balance for growing bones. OOO added to maple syrup grade B can do wonders if the max restore is not enough.
You don't have to get echinacea rt or ooo from MH, but I have tried others and they either are not palatable (collecting dust on shelf) or not as potent. These will be pretty expensive if you get them all at once so acquire them over time unless you can afford to stock up.