Jaters will be aflutter when Kate shows romantic interest in future Jack, but it turns out there's another special person in her life already — someone *** *** ** *** *****, *** ****'* **** a ******.
First part seems easy to me -- someone who was on the plane.
Second part I struggled with, but I think it could be -- but didn't have a ticket. Someone who was on the plane but didn't have a ticket could be Aaron, who was in utero at the time.
If Claire dies and Kate takes Aaron back with her, Aaron could be the "he" Kate says will be waiting for her.