She felt it when One, Two and Three were hurt, the burning on her back woke her from her sleep. It was after the war, she was living in Sirius's old house with Harry and George, Ron had moved out only a few weeks ago, living with Lavender now. She was beyond glad that her room was warded with silencing charms and locking charms as she screamed in pain.
She felt it when four and six were inured in battle, whimpering in silent pain as they ran away, after battle to hide. They were trying to find the others, to get help to stop the slaughter of the remaining few.
She was given two guardians because she was the very last, the strongest and the weakest. She was the strongest if the others remained alive, finding her to help win the battle. She was the weakest if she was the only one left, powerless without her brothers and sisters, the remaining ones from their home planet.
Her protectors were acting as her parents, and it was only convenient for her to hide in the Wizardry World where the magic hid her. But she could stay hidden for long.
Because she felt them.
Four and Six, they were coming to find her. To find Hermione Granger.
Because she was Number Nine.