Megan hadn't thought much of the train leaving. In fact, in her frantic attempt to search for her brother she hadn't even realized that Wayne hadn't chosen to aid her in the search. It wasn't until the locomotive was out of the station and the platform was temporarily cleared did the Hufflepuff notice that she was in fact alone.
After calling for Christopher....then Wayne....then Eloise.... Megan found herself in a confused sort of daze. The muggles around her seemed to notice her initial desperate yells, but thanks to the muggle repelling jumper she wore the potential of starting a scene was understated. Muggles went about their business and Megan, crying, gathered the belongings she'd left behind during the initial escape from Christopher's capture.
Everything was falling apart. How could she have let this happen? How could she have let go of Christopher and..... why had the other two left them behind!? Surely they'd be back right? Surely they'd gone for help? Or perhaps...they'd been captured too! Oh dear god, this couldn't be happening! While searching for the others Megan attempted to use her family two way mirror to contact family members who could help - both her elder brother and father failed to respond to her calls. Which only enticed more frustrated tears.
Finally she'd decided to escape Manchester once an hour long search in and around the station failed her terribly. Megan was in the middle of walking frantically away from the station and debating whether she should attempt apparating to the next town, onto the train south bound, or if she should just make use of the broom she'd been lugging around....when the owl arrived. The words seemed to drown out any thought of getting to family members who could help. They couldn't help. This was her mess and she had to clean it up herself. And if....Wayne and Eloise were already captured...then....well... the point of escaping Hogwarts was pointless now. Her blind loyalty refused to let her carry on with the plan that had been set up for the four them. She wouldn't leave them behind.
She didn't hesitate in her decision. Blind and stupid in her devotion she frantically wrote a reply:
Return to sender: Please, don't hurt him. I'm there now.
Though Megan wasn't entirely certain the owl would make the delivery...she instantly apparated to the front of the station - eager to spot anyone who didn't belong.