I think it is a total misunderstanding. If it was too dangerous for the buses to run then it would be in my opinion too dangerous to walk on the roads too - it isn't like we have winter tires on our feet. She did not need to go out and truthfully she had the right to say sorry not taking my child out on the roads just as much as you have the right to say sorry not taking myself or stroller out on the roads. Should she have confirmed with you yes - that is what the discussion should be about so you know you are on the same page. But she had the right to cancel since it would mean taking her own child out and she didn't feel it was safe meaning it is now up to you to take the walkers to school or keep them home.