Preston does seem to be her maiden name, based on birth entries in the GRO index for the younger children. The most likely marriage seems to have been in Colne in 1820, with her residence being given as "this chapelry".
I haven't found a definite birthplace for her, but my gut feeling is that it will be somewhere in that area, and Pinetree's suggestion will be worth following up. The word in the Blind etc column could be part of the place name, put there for lack of room, and I think it might be Craven, either abbreviated or cut off in the filming/copying. However, would Bolton by Bowland be thought part of Craven? Wouldn't (Forest of) Bowland be more accurate?