Lots of pins!! I pin atleast every 4 square inches.
Start sewing in the center of your quilt, and sew outwards to the edges.
Lengthen your stitch length to atleast 3.5 if not 4.0 Shorter stitches can cause drag.
Good suggestion about releasing some of the pressure off of your pressure foot too.
Bless your heart for making these quilts for kids :D:D:D