Just An Imaginary Friend?

First, to tell you all honestly, until now, I still have doubts if I really have the ability to see the unseen. Sometimes I wonder if I'm just imagining things... After seeing what I am not supposed to see, I would end up having doubts if I had actually seen it. The thing is no matter how many experiences I had, at the end of the day, I'd end up asking myself if ghost or whatever we call them are really true...

Anyway, here's my first story...

When we were kids (my cousins and other relatives) we always played together, from 3 in the afternoon until 6 or 7 in the evening. We lived in a province so we usually played hide and seek and other games we could play at the backyard. I remember we used to play with this little girl, I forgot her name. If remember it clearly, she had a short hair and was wearing a cotton white dress. I just remember the times we played with her, and I know she was always with us, because she smiled at me a lot. (I knew then that she was from anywhere in our neighborhood, we really didn't bother that time.) The thing is, now that we're all grown ups, I and my cousins and the rest, when we talk about our childhood memories, we always talk about the kids we played with. I knew during those times that that little girl was talking and playing with us, and everyone could see her, and now nobody remembers. Just me and my other female cousin.

I know in my heart that she was real. The thing is I don't know where she is now, and I wonder why the others don't remember her. I know her name starts with letter "D". Aside from that, I don't remember anything.

Was she just an imaginary friend?

But why does my other cousin remember her?

I'm really confused until now...