Some good options. Good luck with your project!
Gingham check lover from way back here! I recently had the FC Afghan book from my lib. I've had my eye on the check afghan for a long time but don't want the bulk of the double strand. I also have a check men's cardi pattern from the FC Easy Sweater book. Planning to make it for myself. A while back I also did some gingham check potholders. (Stranded and done double wide, folded in half to encase the WS. Images on my Flickr page. Love 'em!)
Over the wknd I saw some gingham check undies at the local closeout store but was good (I have sufficient) and didn't get them.
ETA: if you want to do a gingham check towel for your sis, cute one here