There was fear in Rosalind's voice. Hermione was loathe to give her any details of her plans before they arrived just in case there were any problems. Rosalind didn't understand how important it was to remain calm and keep secrets. She'd never been forced to learn how to survive in a Death Eater's world. If Rabastan or someone else with equally nefarious plans stopped them, Hermione didn't want the girl to have knowledge of their plans in case she was easily broken under the pressure.