I was so glad someone else remembered this and posted about it…only to discover that this is my thread from 9 1/2 years ago.
I watched the clip from Youtube. Hmmmm…it is similar, but not what I remember. I will concede that it is possible that this is what I saw and got mixed up.
However, my nearly 10 year old memory is identical to mine now. I remember that they were younger than the kids in this movie you linked to. And she didn’t slip in and sit next to him; she just stood by the door and smiled and laughed. The final shot of the movie was Josh laughing.
Still, glad to see the clip.