How do you ask a stranger parent if your kids can meet up again?

Hi all,My girl is 9 and is extremely shy. She struggles to make friends because of this but when we went to the park last weekend she made a friend called Victoria. She spent ages playing with her, and it was wonderful to see them bonding and communicating. I was so happy for her we stayed much longer than we normally would.But my question is, would it have been inappropriate for me to find Victoria’s parent and ask for their number so our kids could meet again? How should I have asked?This park was very far from our house so the girls probably won’t see each other in the neighbourhood. I hate myself now for not asking the parent, but I couldn’t figure out a way to say it that wasn’t creepy or random.Would you be okay with being asked?EDIT: would like to point out I am not her biological Mum and haven’t had care of her for very long. Hence being new at these situations. via /r/Parenting https://ift.tt/2JZE1VR