fleece makes great backs---remember to (smooth) it, not stretch it- lots of pins (starch really is just wasting the starch)
great for tied quilts- she could do the pillow case (birthing) method to put it together- top stitch around the edges- then add ties to hold it all together- really makes it easier than quilting-
if quilting is the desired finish lengthen the stitch length, and do a simple wide cross hatch or stitch in the ditch maybe around each large block-minimum quilting necessary. he will love it & so will she
as for batting- if she wants it to be (lofty) cozy warm add batting---he will be sent somewhere else when done with boot camp-===could be cold---it is a personal choice- i live in northern michigan & tend to add batting -- but some people make them without...one thing is the batting does kind of (stablize)the fleece- especially if using warm & natural or a 'like' batting...if you do go with batting the quilting does need to be the amount the batting recommends...so w&n is a good choice- you don't want one that needs to be quilted every 2".