Who wrote HAEWAFY?

[BrokenHearted]

As I was listening Has Anyone Every Written Anything For You today, I noticed that at the very end, there's this little sound almost in the background that sounds similar to I Can't Wait (I know that made no sense ) And in a video I saw awhile back, Stevie was talking about how she wrote it on her piano in the house, but it's writing is credited to "Stevie Nicks; Keith Olsen" and Keith also helped write I Can't Wait... So, does anyone know if that little bit that comes in right about 4:08 was lifted from I Can't Wait to sort of open and close the album? And does anyone know if Stevie wrote the words and music or just the words to this song?

I promise this all makes sense in my head...

Thanks in advance