Bobbie wanted an excuse not to go, but try as she would she couldn't think of a good one.

And just when she felt that all was lost, her frock caught on a big nail by the kitchen door and there was a great criss-cross tear all along the front of the skirt.

I assure you this was really an accident.

So the others pitied her and went without her, for there was no time for her to change, because they were rather late already and had to hurry to the station to catch the train.
When they had gone, Bobbie put on her everyday frock, and went down to the railway.

She did not go into the station, but she went along the line to the end of the platform where the engine is when the down train is alongside the platform--the place where there are a water tank and a long, limp, leather hose, like an elephant's trunk.