Miss Rottenmeier is the housekeeper at Clara's home in Frankfort. She is displeased when she first meets Heidi. Heidi looks odd to her in her plain woolen dress and smushed straw hat over her short curls. Miss Rottenmeier asks Heidi her age and is worried that she is only eight, when Clara, whose companion she is intended to be, is twelve. She is shocked when Heidi informs her that she doesn't know how to read. Miss Rottenmeier, overall, is startled and unhappy with Heidi, telling Dete the little girl is unsuitable. Dete, however, defends her choice, saying it was requested she bring Clara a companion out of the ordinary, which is what Heidi is.

Heidi continues to say things to Miss Rottenmeier—and do things—which make the older woman unhappy. Heidi speaks to the servant Sebastian as an equal and, without realizing it, later makes a mess in the house, both of which contribute to the housekeeper's conviction that Heidi is unsuitable to be there. She brings in kittens, and she cannot seem to conform to Miss Rottenmeier's ideas of suitable behavior for a middle-class girl. Finally, Heidi decides to leave. When Miss Rottenmeier accuses her of being ungrateful for being accepted into such a good home, Heidi has an outburst and says:

Indeed I only want to go home, for if I stay so long away Snowflake will begin crying again, and grandmother is waiting for me, and Greenfinch will get beaten, because I am not there to give Peter any cheese, and I can never see how the sun says good-night to the mountains; and if the great bird were to fly over Frankfurt he would croak louder than ever about people huddling all together and teaching each other bad things, and not going to live up on the rocks, where it is so much better.

This shocks Miss Rottenmeier but also begins to soften her toward the girl.