Sentence 1: Libby was walking through the mall with her nanny. 
 Sentence 3: Nanny did not notice Libby had stopped and kept walking 
 Sentence 4:  Libby suddenly realized she was alone 
 Sentence 5:  Libby cried until a store worker helped her find her nanny 
 Option 1: Libby told her nanny to stop walking to look at a store window. 
 Option 2: Libby stopped to look at a store window.