I looked it up, and it's a darling BOM with all snowmen in the first row. I subscribed so I can see what the rest of the rows will be. Here's the link -
http://quiltdoodledesigns.blogspot.c....html?spref=bl
In a row quilt, the height of the first row really doesn't matter. However, the length of the row (and the width of each block in the row) - which you didn't measure yet - may matter quite a bit if it doesn't match up to the remaining rows. So... it's time to work on your scant quarter inch seam. Don't be discouraged, because just about every new quilter has trouble with blocks that come out too small at first. On the next row, be sure that each block measures true to whatever it's supposed to be (10.5"?) and that the entire row measures 58.5". You may need to go back to row #1 and fix it, or you may want to just add some fabric to the ends if it's too short - that's up to you. Don't give up! You can do this!