In a recipe like this, is the 3 lbs of peaches before you've cut them up? (Really, I want to know if it includes the pits as part of the weight.)

Katie, not 100% reliable but close.

If a recipe says "x lbs ingredient, chopped" it means buy or weigh the amount specified and then prepare -chop, etc.

If a recipe says "y cups chopped ingredient" it means prepare the specified shape and then measure volume.

I would think the weight is for peaches which have been pitted, but not peeled, because she says she doesn't peel hers. Pits don't account for much weight in relation to the amount of flesh, though, and I don't think it would so critical to have precisely 3 pounds. I also think it could be rather tricky to get exact weight, since peaches do vary slightly. So if you had slightly more or even slightly less I doubt it will wreck the fruit butter.