Sara, Isla, Delilah, the two girls in the two classes? Sara and Isla have at least some story to them. The others are basically an intro and then "Work in Progress." But Isla's got more of a story so far, so I'd guess progress on that before touching the others? (But that's an educated guess from the position of what makes sense to me. If he's had work done on the others that just needed polishing, I suppose the first parts of their stories might be included. It's just 0.7, none of the stories have to be in "complete" state until it hits 1.0.)
Continuing with Isla might also tied into more story with Celia.