Vancouver is a city on the north bank of the Columbia River in the U.S. state of Washington and the county seat of Clark County.
The width of the twin quilt is 66 +12 (for the two extra columns of 9 patches) + 4 (for the two extra strips of sashing) =82, which is a bit wider than your target of 78, but close enough. Plus, it's nice to have it a bit too large than a bit too small.
Standard Toddler Quilt. If you buy a toddler quilt from a store, it can be anywhere from 36 by 50 inches to 46 by 70 inches, depending on the manufacturer. The package should state whether the quilt is for a crib mattress or twin, and additionally, it should always provide the dimensions. If you are buying a handmade toddler quilt, the sizes vary.