I also use the YLI glazed cotton - I would take the large spool (1000 yds) and its only $8.....You would have stuff returned.
I quilted a king size quilt last summer - and it had ALOT of quilting on it - I used 4 spools of the gutterman glazed cotton thread. I had leftover on the 4th spool. Those spools don't have as many yds as the YLI.
Does the Amish lady have a particular type of thread she prefers? I know that I'm picky if i can be - for ex: can't stand Coats & Clark quilting thread - Gutterman is OK, but prefer the YLI..