I think it's unlikely that one of the girls will catch up with Ray, but Jessica is certainly far and away best placed to. Roxanne is really improving, but it's still difficult to tell what Zoe may be capable of as she spends rather a lot of time being physically supported by her partner in one way or another. Apart from his clearly superior skating ability, what makes Ray lovely to watch is his natural sense of rhythm. Despite saying that she's not a dancer, Jessica isn't bad in this area, whereas Zoe moves like a marionette. It's still early days, though, and maybe she will improve. She'll need to let go of her partner first, though.