Kim -
The scant .25 inch is troublesome for new quilters. It sounds as if you are correct that you need to work on that. The biggest thing, I think, is that you want ALL your blocks to finish the same size. So if you are making a wall hanging or table topper where size is not critical you can continue with your construction the same way you did with your first block.
If you are constructing a bed quilt or something that size is critical, then you may want to use some scrap fabric and make a few trial blocks and figure out where that scant .25 inch is on your machine. Just a note - many .25 inch feet generate a larger seam than that scant .25.