What wakes Anne Frank up at the beginning of the fourth scene?

In the play The Diary of Anne Frank in Act I, scene 4, it isn't clear. Anne is having nightmares and screaming, but she is still quite asleep at this point. Because being heard is dangerous for them, Dussel tries to wake her, and Mrs Frank, her mother, takes her into her arms to do the same and comfort her, but it isn't clear whether either of them woke her, or she woke up because of the nightmare itself. As she is held, she gradually comes our of the nightmare, so perhaps the best answer is her mother.