In 900 years of time and space I've never met anyone who wasn't important before.
Joy woke up in her bedroom. For a moment she had no idea where she was. Then she remembered and began sobbing anew. After a while, Joy stopped. She started thinking about how lucky she was that the Doctor had taken her in. A question formed in her brain and spread to her lips. She went to find the Doctor to ask him.
"How'd you sleep?", he asked. "Fine. Thank you." she replied. Then she asked, "Why did you take me? Thousands of children's' parents die every day. Why choose me? I'm not important." The Doctor looked at her in amazement. "Who said you aren't important?" he asked. "Every single person in the universe is important, even if they don't realize it." "I chose you because I happened to be next door when I saw your parents crash into a tree. I knew that I couldn't just leave you." She looked at him with wonder in her eyes. Then, she hugged him and said, "Thank you!" "You're very welcome." he said. "Where do you want to go now?" She thought about it for a minute, then she said, "If you're going to be my dad, can we find me a mom?" The Doctor thought about it. "OK." he said. "I guess we could get my wife."
He went to the library and uploaded her from the computer. "Hello sweetie!" she said. She looked at Joy in surprise. "Who is this?" The Doctor replied, "This is Joy. She's an orphan, so I sort of adopted her. She needs a mother." River smiled at Joy. "I would love to be a mother!" she exclaimed joyfully. "I will come and travel with you." Then, looking at Joy she said, "Hello, Joy. I'm River Song. I'll be your new mother if you'll let me." Joy smiled at her and said, "I would love you to my mom!" They hugged and the Doctor knew that they were going to be alright.