Erin Hunter said this quote

There was a pause as Leopardstar strained to take a breath, and Mistyfoot half rose, ready to call for help. Then Leopardstar relaxed again. I am sorry not to have known the joy of having kits. There was a time when I thought it might happen, but it was not to be. Her words faded away as though she was picturing something she had dreamed of long ago. Perhaps it was for the best. But I would have been proud to call you my daughter, Mistyfoot.