The recipe I'm using calls for sweet butter, but isn't sweet butter just regular unsalted butter? I'm asking bc in her other recipes it says to use unsalted butter. The recipe itself doesn't call for any salt. So I guess my question is what am I supposed to use? Unsalted?

to me sweet butter is just regular butter. Land o lakes reads "sweet cream butter" on the package.

Definition:
"Butter
A solid fat made from churning the fat from milk or cream until it solidifies. It is a water-in-oil emulsion, comprised of over 80% milkfat, but also containing water in the form of tiny droplets, perhaps some milk solids-not-fat, with or without salt; the texture is a result of working/kneading during processing at appropriate temperatures, to establish fat crystalline network that results in desired smoothness (compare butter with melted and recrystallized butter); used as a spread, a cooking fat, or a baking ingredient. Unsalted butter is preferred over salted butter because it permits greater leeway in seasoning recipes to taste. Butter will keep, well wrapped, for 1 month in the refrigerator or for up to 6 months in the freezer. "

"Sweet butter
Unsalted butter"

"Sweet cream butter
Lightly salted butter "

Butter - Explore the History and Making of Butter.
http://webexhibits.org/butter/index.html