So my prediction of having the cross stitch complete by the end of last weekend was wrong. I have all the stitching done, just need to do back stitching and some french knots (eurgh!).
Got some advice from my friend about what to back-stitch; sometimes I find I stare at it too long to be objective anymore! I think I'm going to go quite minimal, and get their names and date on it.
Annoyingly, I'm spending all day tomorrow with my science club at an event, so won't get chance to finish until Sunday. But I will post when I do!