DH made that reservation so I don't have an email for it and since I've cancelled it's not in MDE anymore. I'll send him a text and see if he still has the confirmation email, however it's unlikely as he usually deletes everything.
Sorry I just found this My idea would to been to have Shelby add JaycoFlo onto her existing reservation then once added drop her from it remove Shelby's Credit card info and add Jayco's
Or with today's technology... Have a 3-way conference call (Shelby, JaycoFlo and WDW Reservations) and have ONE CM deal with BOTH the cancellation and the Reservation. Perhaps the CM would have done exactly what Mike suggested too.