The himalayan salt lick is fantastic, but I must warn you – they eat the jolly stall snacks in about a day or less. But she'll love the himalayan salt lick just like she would the jolly stall snack –*except she can't take bites out of it!
As for the muscle... She doesn't need a muscle building supplement –*she's malnourished right now, and young. As her condition improves, her body will get healthier and healthier, and muscle will start to develop as you work her. Also, as she grows older, she'll have more of an ability to grow muscle. Instead, try a weight gain supplement, a multi-purpose "complete" supplement, a vitamin supplement, joint, hoof, etc. :) That'll benefit her way more.
Mudpie loves his jolly ball! He plays with it all the time. Some horses just don't play with them, but some love it! It all depends on your dear girl(: I haven't had a chance to look at the deworming pack you want to buy, but just as a disclaimer, it's not enough to just switch from one to another... For example, you wouldn't just do pyrantel pamoate one time and then ivermectin, and then pyrantel pamoate again. Does that make sense? XD
The hills were bathed in moonlight, the shadows not so stark;
Silver light reflected off his brown hide as he held me in the dark
– I love you, Mudpie!