Poor SUSIE!
Poor Tink, too.
Is this the same thing she had before? It sounds like it. Why the heck can't the vet make her STAY well? It just seems crazy that she keeps getting one thing after another.
I wonder if there is something you can give her to boost her immune system and maybe it will help her stay well?
I hope she's better soon. Tell her Brea and Skyla send their love.