why did rosa huberman make an unplanned visit to liesels school?

Rosa made the trip to tell Liesel that Max was awake and out of his coma.She had to tell her in code to come home.

Rosa made the trip to tell Liesel that Max was awake and out of his coma. She had to tell her in code to come home.

She answered a promise to Liesel. This shows that the crusty Rosa does, indeed, have a heart - and that Liesel has earned not only Rosa's love, but also her respect.