Master Kelb,
Just to ensure that confusion does not exist in your trades, Equitem Sprig does not make Potions. She does, however, make Elixirs. They are both imbibed, but the difference is that Elixirs are alchemical (and have more limited healing capabilities), where Potions are...in a sense...bottled Earth magic.
As an example, an Alchemist could make the following Elixirs:
Cure Light Damage (which is as strong as a Cure Light Wounds spell)
Antidote (which can remove effects that alter your ability to function, such as Laugh, Nausea, Vertigo, Feeblemind, Intoxicate, and Paranoia)
Poison Shield (which despite being an Earth spell, cannot be placed in a Potion, only an Elixir)
A Potion Maker, however, can make a number of effects, such as healing or protectives. This is not to say that Alchemists cannot assist in supplementing you with healing items, but they tend to lack the specialization that a Potion Maker provides.
I hope that helps.
-Dominus Zeth