There were two options for Rosalind if Hermione couldn't get her tucked away somewhere safe. Neither of them were particularly good. She would either be killed by the father of her child merely for being an embarrassment and an inconvenience or she would have to grow tougher, stronger, harder to survive in the world. Much like Hermione had to do twenty years earlier. Was that why she felt such a strong desire to keep her safe? Usually she didn't care. She knew it was the truth whether she wanted to consider it or not. Rosalind was a chance to prevent what happened to Hermione from happening to another.